Import hashbrown-0.9.1 am: cdc803b2d8
Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/hashbrown/+/1493419
Change-Id: Iab874ec814955d6ddca8572af67579bbeb3c14b7
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
new file mode 100644
index 0000000..845b5e7
--- /dev/null
+++ b/.cargo_vcs_info.json
@@ -0,0 +1,5 @@
+{
+ "git": {
+ "sha1": "34c11891e13fa3c0d08b0540e869aace9d347c26"
+ }
+}
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6936990
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/target
+**/*.rs.bk
+Cargo.lock
diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..8f2981a
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,20 @@
+// This file is generated by cargo2android.py --device --run --dependencies.
+
+rust_library {
+ name: "libhashbrown",
+ host_supported: true,
+ crate_name: "hashbrown",
+ srcs: ["src/lib.rs"],
+ edition: "2018",
+ features: [
+ "ahash",
+ "default",
+ "inline-more",
+ ],
+ rustlibs: [
+ "libahash",
+ ],
+}
+
+// dependent_library ["feature_list"]
+// ahash-0.4.6
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..b6eb671
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,294 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+## [Unreleased]
+
+## [v0.9.1] - 2020-09-28
+
+## Added
+- Added safe methods to `RawTable` (#202):
+ - `get`: `find` and `as_ref`
+ - `get_mut`: `find` and `as_mut`
+ - `insert_entry`: `insert` and `as_mut`
+ - `remove_entry`: `find` and `remove`
+ - `erase_entry`: `find` and `erase`
+
+## Changed
+- Removed `from_key_hashed_nocheck`'s `Q: Hash`. (#200)
+- Made `RawTable::drain` safe. (#201)
+
+## [v0.9.0] - 2020-09-03
+
+### Fixed
+- `drain_filter` now removes and yields items that do match the predicate,
+ rather than items that don't. This is a **breaking change** to match the
+ behavior of the `drain_filter` methods in `std`. (#187)
+
+### Added
+- Added `replace_entry_with` to `OccupiedEntry`, and `and_replace_entry_with` to `Entry`. (#190)
+- Implemented `FusedIterator` and `size_hint` for `DrainFilter`. (#188)
+
+### Changed
+- The minimum Rust version has been bumped to 1.36 (due to `crossbeam` dependency). (#193)
+- Updated `ahash` dependency to 0.4. (#198)
+- `HashMap::with_hasher` and `HashSet::with_hasher` are now `const fn`. (#195)
+- Removed `T: Hash + Eq` and `S: BuildHasher` bounds on `HashSet::new`,
+ `with_capacity`, `with_hasher`, and `with_capacity_and_hasher`. (#185)
+
+## [v0.8.2] - 2020-08-08
+
+### Changed
+- Avoid closures to improve compile times. (#183)
+- Do not iterate to drop if empty. (#182)
+
+## [v0.8.1] - 2020-07-16
+
+### Added
+- Added `erase` and `remove` to `RawTable`. (#171)
+- Added `try_with_capacity` to `RawTable`. (#174)
+- Added methods that allow re-using a `RawIter` for `RawDrain`,
+ `RawIntoIter`, and `RawParIter`. (#175)
+- Added `reflect_remove` and `reflect_insert` to `RawIter`. (#175)
+- Added a `drain_filter` function to `HashSet`. (#179)
+
+### Changed
+- Deprecated `RawTable::erase_no_drop` in favor of `erase` and `remove`. (#176)
+- `insert_no_grow` is now exposed under the `"raw"` feature. (#180)
+
+## [v0.8.0] - 2020-06-18
+
+### Fixed
+- Marked `RawTable::par_iter` as `unsafe`. (#157)
+
+### Changed
+- Reduced the size of `HashMap`. (#159)
+- No longer create tables with a capacity of 1 element. (#162)
+- Removed `K: Eq + Hash` bounds on `retain`. (#163)
+- Pulled in `HashMap` changes from rust-lang/rust (#164):
+ - `extend_one` support on nightly.
+ - `CollectionAllocErr` renamed to `TryReserveError`.
+ - Added `HashSet::get_or_insert_owned`.
+ - `Default` for `HashSet` no longer requires `T: Eq + Hash` and `S: BuildHasher`.
+
+## [v0.7.2] - 2020-04-27
+
+### Added
+- Added `or_insert_with_key` to `Entry`. (#152)
+
+### Fixed
+- Partially reverted `Clone` optimization which was unsound. (#154)
+
+### Changed
+- Disabled use of `const-random` by default, which prevented reproducible builds. (#155)
+- Optimized `repeat` function. (#150)
+- Use `NonNull` for buckets, which improves codegen for iterators. (#148)
+
+## [v0.7.1] - 2020-03-16
+
+### Added
+- Added `HashMap::get_key_value_mut`. (#145)
+
+### Changed
+- Optimized `Clone` implementation. (#146)
+
+## [v0.7.0] - 2020-01-31
+
+### Added
+- Added a `drain_filter` function to `HashMap`. (#135)
+
+### Changed
+- Updated `ahash` dependency to 0.3. (#141)
+- Optimized set union and intersection. (#130)
+- `raw_entry` can now be used without requiring `S: BuildHasher`. (#123)
+- `RawTable::bucket_index` can now be used under the `raw` feature. (#128)
+
+## [v0.6.3] - 2019-10-31
+
+### Added
+- Added an `ahash-compile-time-rng` feature (enabled by default) which allows disabling the
+ `compile-time-rng` feature in `ahash` to work around a Cargo bug. (#125)
+
+## [v0.6.2] - 2019-10-23
+
+### Added
+- Added an `inline-more` feature (enabled by default) which allows choosing a tradeoff between
+ runtime performance and compilation time. (#119)
+
+## [v0.6.1] - 2019-10-04
+
+### Added
+- Added `Entry::insert` and `RawEntryMut::insert`. (#118)
+
+### Changed
+- `Group::static_empty` was changed from a `const` to a `static` (#116).
+
+## [v0.6.0] - 2019-08-13
+
+### Fixed
+- Fixed AHash accidentally depending on `std`. (#110)
+
+### Changed
+- The minimum Rust version has been bumped to 1.32 (due to `rand` dependency).
+
+## ~~[v0.5.1] - 2019-08-04~~
+
+This release was _yanked_ due to a breaking change for users of `no-default-features`.
+
+### Added
+- The experimental and unsafe `RawTable` API is available under the "raw" feature. (#108)
+- Added entry-like methods for `HashSet`. (#98)
+
+### Changed
+- Changed the default hasher from FxHash to AHash. (#97)
+- `hashbrown` is now fully `no_std` on recent Rust versions (1.36+). (#96)
+
+### Fixed
+- We now avoid growing the table during insertions when it wasn't necessary. (#106)
+- `RawOccupiedEntryMut` now properly implements `Send` and `Sync`. (#100)
+- Relaxed `lazy_static` version. (#92)
+
+## [v0.5.0] - 2019-06-12
+
+### Fixed
+- Resize with a more conservative amount of space after deletions. (#86)
+
+### Changed
+- Exposed the Layout of the failed allocation in CollectionAllocErr::AllocErr. (#89)
+
+## [v0.4.0] - 2019-05-30
+
+### Fixed
+- Fixed `Send` trait bounds on `IterMut` not matching the libstd one. (#82)
+
+## [v0.3.1] - 2019-05-30
+
+### Fixed
+- Fixed incorrect use of slice in unsafe code. (#80)
+
+## [v0.3.0] - 2019-04-23
+
+### Changed
+- Changed shrink_to to not panic if min_capacity < capacity. (#67)
+
+### Fixed
+- Worked around emscripten bug emscripten-core/emscripten-fastcomp#258. (#66)
+
+## [v0.2.2] - 2019-04-16
+
+### Fixed
+- Inlined non-nightly lowest_set_bit_nonzero. (#64)
+- Fixed build on latest nightly. (#65)
+
+## [v0.2.1] - 2019-04-14
+
+### Changed
+- Use for_each in map Extend and FromIterator. (#58)
+- Improved worst-case performance of HashSet.is_subset. (#61)
+
+### Fixed
+- Removed incorrect debug_assert. (#60)
+
+## [v0.2.0] - 2019-03-31
+
+### Changed
+- The code has been updated to Rust 2018 edition. This means that the minimum
+ Rust version has been bumped to 1.31 (2018 edition).
+
+### Added
+- Added `insert_with_hasher` to the raw_entry API to allow `K: !(Hash + Eq)`. (#54)
+- Added support for using hashbrown as the hash table implementation in libstd. (#46)
+
+### Fixed
+- Fixed cargo build with minimal-versions. (#45)
+- Fixed `#[may_dangle]` attributes to match the libstd `HashMap`. (#46)
+- ZST keys and values are now handled properly. (#46)
+
+## [v0.1.8] - 2019-01-14
+
+### Added
+- Rayon parallel iterator support (#37)
+- `raw_entry` support (#31)
+- `#[may_dangle]` on nightly (#31)
+- `try_reserve` support (#31)
+
+### Fixed
+- Fixed variance on `IterMut`. (#31)
+
+## [v0.1.7] - 2018-12-05
+
+### Fixed
+- Fixed non-SSE version of convert_special_to_empty_and_full_to_deleted. (#32)
+- Fixed overflow in rehash_in_place. (#33)
+
+## [v0.1.6] - 2018-11-17
+
+### Fixed
+- Fixed compile error on nightly. (#29)
+
+## [v0.1.5] - 2018-11-08
+
+### Fixed
+- Fixed subtraction overflow in generic::Group::match_byte. (#28)
+
+## [v0.1.4] - 2018-11-04
+
+### Fixed
+- Fixed a bug in the `erase_no_drop` implementation. (#26)
+
+## [v0.1.3] - 2018-11-01
+
+### Added
+- Serde support. (#14)
+
+### Fixed
+- Make the compiler inline functions more aggressively. (#20)
+
+## [v0.1.2] - 2018-10-31
+
+### Fixed
+- `clear` segfaults when called on an empty table. (#13)
+
+## [v0.1.1] - 2018-10-30
+
+### Fixed
+- `erase_no_drop` optimization not triggering in the SSE2 implementation. (#3)
+- Missing `Send` and `Sync` for hash map and iterator types. (#7)
+- Bug when inserting into a table smaller than the group width. (#5)
+
+## v0.1.0 - 2018-10-29
+
+- Initial release
+
+[Unreleased]: https://github.com/rust-lang/hashbrown/compare/v0.9.1...HEAD
+[v0.9.1]: https://github.com/rust-lang/hashbrown/compare/v0.9.0...v0.9.1
+[v0.9.0]: https://github.com/rust-lang/hashbrown/compare/v0.8.2...v0.9.0
+[v0.8.2]: https://github.com/rust-lang/hashbrown/compare/v0.8.1...v0.8.2
+[v0.8.1]: https://github.com/rust-lang/hashbrown/compare/v0.8.0...v0.8.1
+[v0.8.0]: https://github.com/rust-lang/hashbrown/compare/v0.7.2...v0.8.0
+[v0.7.2]: https://github.com/rust-lang/hashbrown/compare/v0.7.1...v0.7.2
+[v0.7.1]: https://github.com/rust-lang/hashbrown/compare/v0.7.0...v0.7.1
+[v0.7.0]: https://github.com/rust-lang/hashbrown/compare/v0.6.3...v0.7.0
+[v0.6.3]: https://github.com/rust-lang/hashbrown/compare/v0.6.2...v0.6.3
+[v0.6.2]: https://github.com/rust-lang/hashbrown/compare/v0.6.1...v0.6.2
+[v0.6.1]: https://github.com/rust-lang/hashbrown/compare/v0.6.0...v0.6.1
+[v0.6.0]: https://github.com/rust-lang/hashbrown/compare/v0.5.1...v0.6.0
+[v0.5.1]: https://github.com/rust-lang/hashbrown/compare/v0.5.0...v0.5.1
+[v0.5.0]: https://github.com/rust-lang/hashbrown/compare/v0.4.0...v0.5.0
+[v0.4.0]: https://github.com/rust-lang/hashbrown/compare/v0.3.1...v0.4.0
+[v0.3.1]: https://github.com/rust-lang/hashbrown/compare/v0.3.0...v0.3.1
+[v0.3.0]: https://github.com/rust-lang/hashbrown/compare/v0.2.2...v0.3.0
+[v0.2.2]: https://github.com/rust-lang/hashbrown/compare/v0.2.1...v0.2.2
+[v0.2.1]: https://github.com/rust-lang/hashbrown/compare/v0.2.0...v0.2.1
+[v0.2.0]: https://github.com/rust-lang/hashbrown/compare/v0.1.8...v0.2.0
+[v0.1.8]: https://github.com/rust-lang/hashbrown/compare/v0.1.7...v0.1.8
+[v0.1.7]: https://github.com/rust-lang/hashbrown/compare/v0.1.6...v0.1.7
+[v0.1.6]: https://github.com/rust-lang/hashbrown/compare/v0.1.5...v0.1.6
+[v0.1.5]: https://github.com/rust-lang/hashbrown/compare/v0.1.4...v0.1.5
+[v0.1.4]: https://github.com/rust-lang/hashbrown/compare/v0.1.3...v0.1.4
+[v0.1.3]: https://github.com/rust-lang/hashbrown/compare/v0.1.2...v0.1.3
+[v0.1.2]: https://github.com/rust-lang/hashbrown/compare/v0.1.1...v0.1.2
+[v0.1.1]: https://github.com/rust-lang/hashbrown/compare/v0.1.0...v0.1.1
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..7be0341
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,80 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+edition = "2018"
+name = "hashbrown"
+version = "0.9.1"
+authors = ["Amanieu d'Antras <amanieu@gmail.com>"]
+exclude = [".travis.yml", "bors.toml", "/ci/*"]
+description = "A Rust port of Google's SwissTable hash map"
+readme = "README.md"
+keywords = ["hash", "no_std", "hashmap", "swisstable"]
+categories = ["data-structures", "no-std"]
+license = "Apache-2.0/MIT"
+repository = "https://github.com/rust-lang/hashbrown"
+[package.metadata.docs.rs]
+features = ["nightly", "rayon", "serde", "raw"]
+[dependencies.ahash]
+version = "0.4.4"
+optional = true
+default-features = false
+
+[dependencies.alloc]
+version = "1.0.0"
+optional = true
+package = "rustc-std-workspace-alloc"
+
+[dependencies.compiler_builtins]
+version = "0.1.2"
+optional = true
+
+[dependencies.core]
+version = "1.0.0"
+optional = true
+package = "rustc-std-workspace-core"
+
+[dependencies.rayon]
+version = "1.0"
+optional = true
+
+[dependencies.serde]
+version = "1.0.25"
+optional = true
+default-features = false
+[dev-dependencies.doc-comment]
+version = "0.3.1"
+
+[dev-dependencies.lazy_static]
+version = "1.2"
+
+[dev-dependencies.rand]
+version = "0.7.3"
+features = ["small_rng"]
+
+[dev-dependencies.rayon]
+version = "1.0"
+
+[dev-dependencies.rustc-hash]
+version = "=1.0"
+
+[dev-dependencies.serde_test]
+version = "1.0"
+
+[features]
+ahash-compile-time-rng = ["ahash/compile-time-rng"]
+default = ["ahash", "inline-more"]
+inline-more = []
+nightly = []
+raw = []
+rustc-dep-of-std = ["nightly", "core", "compiler_builtins", "alloc", "rustc-internal-api"]
+rustc-internal-api = []
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
new file mode 100644
index 0000000..21bd5c2
--- /dev/null
+++ b/Cargo.toml.orig
@@ -0,0 +1,56 @@
+[package]
+name = "hashbrown"
+version = "0.9.1"
+authors = ["Amanieu d'Antras <amanieu@gmail.com>"]
+description = "A Rust port of Google's SwissTable hash map"
+license = "Apache-2.0/MIT"
+repository = "https://github.com/rust-lang/hashbrown"
+readme = "README.md"
+keywords = ["hash", "no_std", "hashmap", "swisstable"]
+categories = ["data-structures", "no-std"]
+exclude = [".travis.yml", "bors.toml", "/ci/*"]
+edition = "2018"
+
+[dependencies]
+# For the default hasher
+ahash = { version = "0.4.4", optional = true, default-features = false }
+
+# For external trait impls
+rayon = { version = "1.0", optional = true }
+serde = { version = "1.0.25", default-features = false, optional = true }
+
+# When built as part of libstd
+core = { version = "1.0.0", optional = true, package = "rustc-std-workspace-core" }
+compiler_builtins = { version = "0.1.2", optional = true }
+alloc = { version = "1.0.0", optional = true, package = "rustc-std-workspace-alloc" }
+
+[dev-dependencies]
+lazy_static = "1.2"
+rand = { version = "0.7.3", features = ["small_rng"] }
+rayon = "1.0"
+rustc-hash = "=1.0"
+serde_test = "1.0"
+doc-comment = "0.3.1"
+
+[features]
+default = ["ahash", "inline-more"]
+
+ahash-compile-time-rng = ["ahash/compile-time-rng"]
+nightly = []
+rustc-internal-api = []
+rustc-dep-of-std = [
+ "nightly",
+ "core",
+ "compiler_builtins",
+ "alloc",
+ "rustc-internal-api",
+]
+raw = []
+
+# Enables usage of `#[inline]` on far more functions than by default in this
+# crate. This may lead to a performance increase but often comes at a compile
+# time cost.
+inline-more = []
+
+[package.metadata.docs.rs]
+features = ["nightly", "rayon", "serde", "raw"]
diff --git a/LICENSE b/LICENSE
new file mode 120000
index 0000000..6b579aa
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1 @@
+LICENSE-APACHE
\ No newline at end of file
diff --git a/LICENSE-APACHE b/LICENSE-APACHE
new file mode 100644
index 0000000..16fe87b
--- /dev/null
+++ b/LICENSE-APACHE
@@ -0,0 +1,201 @@
+ Apache License
+ Version 2.0, January 2004
+ http://www.apache.org/licenses/
+
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+
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+5. Submission of Contributions. Unless You explicitly state otherwise,
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+ by You to the Licensor shall be under the terms and conditions of
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+ of your accepting any such warranty or additional liability.
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+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
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+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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diff --git a/LICENSE-MIT b/LICENSE-MIT
new file mode 100644
index 0000000..5afc2a7
--- /dev/null
+++ b/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2016 Amanieu d'Antras
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..b3d1a7c
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,19 @@
+name: "hashbrown"
+description: "A Rust port of Google\'s SwissTable hash map"
+third_party {
+ url {
+ type: HOMEPAGE
+ value: "https://crates.io/crates/hashbrown"
+ }
+ url {
+ type: ARCHIVE
+ value: "https://static.crates.io/crates/hashbrown/hashbrown-0.9.1.crate"
+ }
+ version: "0.9.1"
+ license_type: NOTICE
+ last_upgrade_date {
+ year: 2020
+ month: 11
+ day: 9
+ }
+}
diff --git a/MODULE_LICENSE_APACHE2 b/MODULE_LICENSE_APACHE2
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/MODULE_LICENSE_APACHE2
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..46fc303
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1 @@
+include platform/prebuilts/rust:/OWNERS
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2e43171
--- /dev/null
+++ b/README.md
@@ -0,0 +1,126 @@
+hashbrown
+=========
+
+[](https://travis-ci.com/rust-lang/hashbrown)
+[](https://crates.io/crates/hashbrown)
+[](https://docs.rs/hashbrown)
+[](https://github.com/rust-lang/hashbrown)
+
+This crate is a Rust port of Google's high-performance [SwissTable] hash
+map, adapted to make it a drop-in replacement for Rust's standard `HashMap`
+and `HashSet` types.
+
+The original C++ version of SwissTable can be found [here], and this
+[CppCon talk] gives an overview of how the algorithm works.
+
+Since Rust 1.36, this is now the `HashMap` implementation for the Rust standard
+library. However you may still want to use this crate instead since it works
+in environments without `std`, such as embedded systems and kernels.
+
+[SwissTable]: https://abseil.io/blog/20180927-swisstables
+[here]: https://github.com/abseil/abseil-cpp/blob/master/absl/container/internal/raw_hash_set.h
+[CppCon talk]: https://www.youtube.com/watch?v=ncHmEUmJZf4
+
+## [Change log](CHANGELOG.md)
+
+## Features
+
+- Drop-in replacement for the standard library `HashMap` and `HashSet` types.
+- Uses `AHash` as the default hasher, which is much faster than SipHash.
+- Around 2x faster than the previous standard library `HashMap`.
+- Lower memory usage: only 1 byte of overhead per entry instead of 8.
+- Compatible with `#[no_std]` (but requires a global allocator with the `alloc` crate).
+- Empty hash maps do not allocate any memory.
+- SIMD lookups to scan multiple hash entries in parallel.
+
+## Performance
+
+Compared to the previous implementation of `std::collections::HashMap` (Rust 1.35).
+
+With the hashbrown default AHash hasher (not HashDoS-resistant):
+
+```text
+ name oldstdhash ns/iter hashbrown ns/iter diff ns/iter diff % speedup
+ insert_ahash_highbits 20,846 7,397 -13,449 -64.52% x 2.82
+ insert_ahash_random 20,515 7,796 -12,719 -62.00% x 2.63
+ insert_ahash_serial 21,668 7,264 -14,404 -66.48% x 2.98
+ insert_erase_ahash_highbits 29,570 17,498 -12,072 -40.83% x 1.69
+ insert_erase_ahash_random 39,569 17,474 -22,095 -55.84% x 2.26
+ insert_erase_ahash_serial 32,073 17,332 -14,741 -45.96% x 1.85
+ iter_ahash_highbits 1,572 2,087 515 32.76% x 0.75
+ iter_ahash_random 1,609 2,074 465 28.90% x 0.78
+ iter_ahash_serial 2,293 2,120 -173 -7.54% x 1.08
+ lookup_ahash_highbits 3,460 4,403 943 27.25% x 0.79
+ lookup_ahash_random 6,377 3,911 -2,466 -38.67% x 1.63
+ lookup_ahash_serial 3,629 3,586 -43 -1.18% x 1.01
+ lookup_fail_ahash_highbits 5,286 3,411 -1,875 -35.47% x 1.55
+ lookup_fail_ahash_random 12,365 4,171 -8,194 -66.27% x 2.96
+ lookup_fail_ahash_serial 4,902 3,240 -1,662 -33.90% x 1.51
+```
+
+With the libstd default SipHash hasher (HashDoS-resistant):
+
+```text
+ name oldstdhash ns/iter hashbrown ns/iter diff ns/iter diff % speedup
+ insert_std_highbits 32,598 20,199 -12,399 -38.04% x 1.61
+ insert_std_random 29,824 20,760 -9,064 -30.39% x 1.44
+ insert_std_serial 33,151 17,256 -15,895 -47.95% x 1.92
+ insert_erase_std_highbits 74,731 48,735 -25,996 -34.79% x 1.53
+ insert_erase_std_random 73,828 47,649 -26,179 -35.46% x 1.55
+ insert_erase_std_serial 73,864 40,147 -33,717 -45.65% x 1.84
+ iter_std_highbits 1,518 2,264 746 49.14% x 0.67
+ iter_std_random 1,502 2,414 912 60.72% x 0.62
+ iter_std_serial 6,361 2,118 -4,243 -66.70% x 3.00
+ lookup_std_highbits 21,705 16,962 -4,743 -21.85% x 1.28
+ lookup_std_random 21,654 17,158 -4,496 -20.76% x 1.26
+ lookup_std_serial 18,726 14,509 -4,217 -22.52% x 1.29
+ lookup_fail_std_highbits 25,852 17,323 -8,529 -32.99% x 1.49
+ lookup_fail_std_random 25,913 17,760 -8,153 -31.46% x 1.46
+ lookup_fail_std_serial 22,648 14,839 -7,809 -34.48% x 1.53
+```
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+hashbrown = "0.9"
+```
+
+Then:
+
+```rust
+use hashbrown::HashMap;
+
+let mut map = HashMap::new();
+map.insert(1, "one");
+```
+
+This crate has the following Cargo features:
+
+- `nightly`: Enables nightly-only features: `#[may_dangle]`.
+- `serde`: Enables serde serialization support.
+- `rayon`: Enables rayon parallel iterator support.
+- `raw`: Enables access to the experimental and unsafe `RawTable` API.
+- `inline-more`: Adds inline hints to most functions, improving run-time performance at the cost
+ of compilation time. (enabled by default)
+- `ahash`: Compiles with ahash as default hasher. (enabled by default)
+- `ahash-compile-time-rng`: Activates the `compile-time-rng` feature of ahash, to increase the
+ DOS-resistance, but can result in issues for `no_std` builds. More details in
+ [issue#124](https://github.com/rust-lang/hashbrown/issues/124). (enabled by default)
+
+## License
+
+Licensed under either of:
+
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any
+additional terms or conditions.
diff --git a/benches/bench.rs b/benches/bench.rs
new file mode 100644
index 0000000..771e716
--- /dev/null
+++ b/benches/bench.rs
@@ -0,0 +1,260 @@
+// This benchmark suite contains some benchmarks along a set of dimensions:
+// Hasher: std default (SipHash) and crate default (AHash).
+// Int key distribution: low bit heavy, top bit heavy, and random.
+// Task: basic functionality: insert, insert_erase, lookup, lookup_fail, iter
+#![feature(test)]
+
+extern crate test;
+
+use test::{black_box, Bencher};
+
+use hashbrown::hash_map::DefaultHashBuilder;
+use hashbrown::HashMap;
+use std::collections::hash_map::RandomState;
+
+const SIZE: usize = 1000;
+
+// The default hashmap when using this crate directly.
+type AHashMap<K, V> = HashMap<K, V, DefaultHashBuilder>;
+// This uses the hashmap from this crate with the default hasher of the stdlib.
+type StdHashMap<K, V> = HashMap<K, V, RandomState>;
+
+// A random key iterator.
+#[derive(Clone, Copy)]
+struct RandomKeys {
+ state: usize,
+}
+
+impl RandomKeys {
+ fn new() -> Self {
+ RandomKeys { state: 0 }
+ }
+}
+
+impl Iterator for RandomKeys {
+ type Item = usize;
+ fn next(&mut self) -> Option<usize> {
+ // Add 1 then multiply by some 32 bit prime.
+ self.state = self.state.wrapping_add(1).wrapping_mul(3787392781);
+ Some(self.state)
+ }
+}
+
+macro_rules! bench_suite {
+ ($bench_macro:ident, $bench_ahash_serial:ident, $bench_std_serial:ident,
+ $bench_ahash_highbits:ident, $bench_std_highbits:ident,
+ $bench_ahash_random:ident, $bench_std_random:ident) => {
+ $bench_macro!($bench_ahash_serial, AHashMap, 0..);
+ $bench_macro!($bench_std_serial, StdHashMap, 0..);
+ $bench_macro!(
+ $bench_ahash_highbits,
+ AHashMap,
+ (0..).map(usize::swap_bytes)
+ );
+ $bench_macro!(
+ $bench_std_highbits,
+ StdHashMap,
+ (0..).map(usize::swap_bytes)
+ );
+ $bench_macro!($bench_ahash_random, AHashMap, RandomKeys::new());
+ $bench_macro!($bench_std_random, StdHashMap, RandomKeys::new());
+ };
+}
+
+macro_rules! bench_insert {
+ ($name:ident, $maptype:ident, $keydist:expr) => {
+ #[bench]
+ fn $name(b: &mut Bencher) {
+ let mut m = $maptype::with_capacity_and_hasher(SIZE, Default::default());
+ b.iter(|| {
+ m.clear();
+ for i in ($keydist).take(SIZE) {
+ m.insert(i, i);
+ }
+ black_box(&mut m);
+ })
+ }
+ };
+}
+
+bench_suite!(
+ bench_insert,
+ insert_ahash_serial,
+ insert_std_serial,
+ insert_ahash_highbits,
+ insert_std_highbits,
+ insert_ahash_random,
+ insert_std_random
+);
+
+macro_rules! bench_insert_erase {
+ ($name:ident, $maptype:ident, $keydist:expr) => {
+ #[bench]
+ fn $name(b: &mut Bencher) {
+ let mut base = $maptype::default();
+ for i in ($keydist).take(SIZE) {
+ base.insert(i, i);
+ }
+ let skip = $keydist.skip(SIZE);
+ b.iter(|| {
+ let mut m = base.clone();
+ let mut add_iter = skip.clone();
+ let mut remove_iter = $keydist;
+ // While keeping the size constant,
+ // replace the first keydist with the second.
+ for (add, remove) in (&mut add_iter).zip(&mut remove_iter).take(SIZE) {
+ m.insert(add, add);
+ black_box(m.remove(&remove));
+ }
+ black_box(m);
+ })
+ }
+ };
+}
+
+bench_suite!(
+ bench_insert_erase,
+ insert_erase_ahash_serial,
+ insert_erase_std_serial,
+ insert_erase_ahash_highbits,
+ insert_erase_std_highbits,
+ insert_erase_ahash_random,
+ insert_erase_std_random
+);
+
+macro_rules! bench_lookup {
+ ($name:ident, $maptype:ident, $keydist:expr) => {
+ #[bench]
+ fn $name(b: &mut Bencher) {
+ let mut m = $maptype::default();
+ for i in $keydist.take(SIZE) {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ for i in $keydist.take(SIZE) {
+ black_box(m.get(&i));
+ }
+ })
+ }
+ };
+}
+
+bench_suite!(
+ bench_lookup,
+ lookup_ahash_serial,
+ lookup_std_serial,
+ lookup_ahash_highbits,
+ lookup_std_highbits,
+ lookup_ahash_random,
+ lookup_std_random
+);
+
+macro_rules! bench_lookup_fail {
+ ($name:ident, $maptype:ident, $keydist:expr) => {
+ #[bench]
+ fn $name(b: &mut Bencher) {
+ let mut m = $maptype::default();
+ let mut iter = $keydist;
+ for i in (&mut iter).take(SIZE) {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ for i in (&mut iter).take(SIZE) {
+ black_box(m.get(&i));
+ }
+ })
+ }
+ };
+}
+
+bench_suite!(
+ bench_lookup_fail,
+ lookup_fail_ahash_serial,
+ lookup_fail_std_serial,
+ lookup_fail_ahash_highbits,
+ lookup_fail_std_highbits,
+ lookup_fail_ahash_random,
+ lookup_fail_std_random
+);
+
+macro_rules! bench_iter {
+ ($name:ident, $maptype:ident, $keydist:expr) => {
+ #[bench]
+ fn $name(b: &mut Bencher) {
+ let mut m = $maptype::default();
+ for i in ($keydist).take(SIZE) {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ for i in &m {
+ black_box(i);
+ }
+ })
+ }
+ };
+}
+
+bench_suite!(
+ bench_iter,
+ iter_ahash_serial,
+ iter_std_serial,
+ iter_ahash_highbits,
+ iter_std_highbits,
+ iter_ahash_random,
+ iter_std_random
+);
+
+#[bench]
+fn clone_small(b: &mut Bencher) {
+ let mut m = HashMap::new();
+ for i in 0..10 {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ black_box(m.clone());
+ })
+}
+
+#[bench]
+fn clone_from_small(b: &mut Bencher) {
+ let mut m = HashMap::new();
+ let mut m2 = HashMap::new();
+ for i in 0..10 {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ m2.clone_from(&m);
+ black_box(&mut m2);
+ })
+}
+
+#[bench]
+fn clone_large(b: &mut Bencher) {
+ let mut m = HashMap::new();
+ for i in 0..1000 {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ black_box(m.clone());
+ })
+}
+
+#[bench]
+fn clone_from_large(b: &mut Bencher) {
+ let mut m = HashMap::new();
+ let mut m2 = HashMap::new();
+ for i in 0..1000 {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ m2.clone_from(&m);
+ black_box(&mut m2);
+ })
+}
diff --git a/clippy.toml b/clippy.toml
new file mode 100644
index 0000000..d98bf2c
--- /dev/null
+++ b/clippy.toml
@@ -0,0 +1 @@
+doc-valid-idents = [ "CppCon", "SwissTable", "SipHash", "HashDoS" ]
diff --git a/src/external_trait_impls/mod.rs b/src/external_trait_impls/mod.rs
new file mode 100644
index 0000000..ef49783
--- /dev/null
+++ b/src/external_trait_impls/mod.rs
@@ -0,0 +1,4 @@
+#[cfg(feature = "rayon")]
+pub(crate) mod rayon;
+#[cfg(feature = "serde")]
+mod serde;
diff --git a/src/external_trait_impls/rayon/helpers.rs b/src/external_trait_impls/rayon/helpers.rs
new file mode 100644
index 0000000..9382007
--- /dev/null
+++ b/src/external_trait_impls/rayon/helpers.rs
@@ -0,0 +1,26 @@
+use alloc::collections::LinkedList;
+use alloc::vec::Vec;
+
+use rayon::iter::{IntoParallelIterator, ParallelIterator};
+
+/// Helper for collecting parallel iterators to an intermediary
+pub(super) fn collect<I: IntoParallelIterator>(iter: I) -> (LinkedList<Vec<I::Item>>, usize) {
+ let list = iter
+ .into_par_iter()
+ .fold(Vec::new, |mut vec, elem| {
+ vec.push(elem);
+ vec
+ })
+ .map(|vec| {
+ let mut list = LinkedList::new();
+ list.push_back(vec);
+ list
+ })
+ .reduce(LinkedList::new, |mut list1, mut list2| {
+ list1.append(&mut list2);
+ list1
+ });
+
+ let len = list.iter().map(Vec::len).sum();
+ (list, len)
+}
diff --git a/src/external_trait_impls/rayon/map.rs b/src/external_trait_impls/rayon/map.rs
new file mode 100644
index 0000000..334f8bb
--- /dev/null
+++ b/src/external_trait_impls/rayon/map.rs
@@ -0,0 +1,666 @@
+//! Rayon extensions for `HashMap`.
+
+use crate::hash_map::HashMap;
+use core::fmt;
+use core::hash::{BuildHasher, Hash};
+use rayon::iter::plumbing::UnindexedConsumer;
+use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, ParallelIterator};
+
+/// Parallel iterator over shared references to entries in a map.
+///
+/// This iterator is created by the [`par_iter`] method on [`HashMap`]
+/// (provided by the [`IntoParallelRefIterator`] trait).
+/// See its documentation for more.
+///
+/// [`par_iter`]: /hashbrown/struct.HashMap.html#method.par_iter
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+/// [`IntoParallelRefIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefIterator.html
+pub struct ParIter<'a, K, V, S> {
+ map: &'a HashMap<K, V, S>,
+}
+
+impl<'a, K: Sync, V: Sync, S: Sync> ParallelIterator for ParIter<'a, K, V, S> {
+ type Item = (&'a K, &'a V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ unsafe { self.map.table.par_iter() }
+ .map(|x| unsafe {
+ let r = x.as_ref();
+ (&r.0, &r.1)
+ })
+ .drive_unindexed(consumer)
+ }
+}
+
+impl<K, V, S> Clone for ParIter<'_, K, V, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ ParIter { map: self.map }
+ }
+}
+
+impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, S: BuildHasher> fmt::Debug for ParIter<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.iter().fmt(f)
+ }
+}
+
+/// Parallel iterator over shared references to keys in a map.
+///
+/// This iterator is created by the [`par_keys`] method on [`HashMap`].
+/// See its documentation for more.
+///
+/// [`par_keys`]: /hashbrown/struct.HashMap.html#method.par_keys
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+pub struct ParKeys<'a, K, V, S> {
+ map: &'a HashMap<K, V, S>,
+}
+
+impl<'a, K: Sync, V: Sync, S: Sync> ParallelIterator for ParKeys<'a, K, V, S> {
+ type Item = &'a K;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ unsafe { self.map.table.par_iter() }
+ .map(|x| unsafe { &x.as_ref().0 })
+ .drive_unindexed(consumer)
+ }
+}
+
+impl<K, V, S> Clone for ParKeys<'_, K, V, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ ParKeys { map: self.map }
+ }
+}
+
+impl<K: fmt::Debug + Eq + Hash, V, S: BuildHasher> fmt::Debug for ParKeys<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.keys().fmt(f)
+ }
+}
+
+/// Parallel iterator over shared references to values in a map.
+///
+/// This iterator is created by the [`par_values`] method on [`HashMap`].
+/// See its documentation for more.
+///
+/// [`par_values`]: /hashbrown/struct.HashMap.html#method.par_values
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+pub struct ParValues<'a, K, V, S> {
+ map: &'a HashMap<K, V, S>,
+}
+
+impl<'a, K: Sync, V: Sync, S: Sync> ParallelIterator for ParValues<'a, K, V, S> {
+ type Item = &'a V;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ unsafe { self.map.table.par_iter() }
+ .map(|x| unsafe { &x.as_ref().1 })
+ .drive_unindexed(consumer)
+ }
+}
+
+impl<K, V, S> Clone for ParValues<'_, K, V, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ ParValues { map: self.map }
+ }
+}
+
+impl<K: Eq + Hash, V: fmt::Debug, S: BuildHasher> fmt::Debug for ParValues<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.values().fmt(f)
+ }
+}
+
+/// Parallel iterator over mutable references to entries in a map.
+///
+/// This iterator is created by the [`par_iter_mut`] method on [`HashMap`]
+/// (provided by the [`IntoParallelRefMutIterator`] trait).
+/// See its documentation for more.
+///
+/// [`par_iter_mut`]: /hashbrown/struct.HashMap.html#method.par_iter_mut
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+/// [`IntoParallelRefMutIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefMutIterator.html
+pub struct ParIterMut<'a, K, V, S> {
+ map: &'a mut HashMap<K, V, S>,
+}
+
+impl<'a, K: Send + Sync, V: Send, S: Send> ParallelIterator for ParIterMut<'a, K, V, S> {
+ type Item = (&'a K, &'a mut V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ unsafe { self.map.table.par_iter() }
+ .map(|x| unsafe {
+ let r = x.as_mut();
+ (&r.0, &mut r.1)
+ })
+ .drive_unindexed(consumer)
+ }
+}
+
+impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, S: BuildHasher> fmt::Debug
+ for ParIterMut<'_, K, V, S>
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.iter().fmt(f)
+ }
+}
+
+/// Parallel iterator over mutable references to values in a map.
+///
+/// This iterator is created by the [`par_values_mut`] method on [`HashMap`].
+/// See its documentation for more.
+///
+/// [`par_values_mut`]: /hashbrown/struct.HashMap.html#method.par_values_mut
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+pub struct ParValuesMut<'a, K, V, S> {
+ map: &'a mut HashMap<K, V, S>,
+}
+
+impl<'a, K: Send, V: Send, S: Send> ParallelIterator for ParValuesMut<'a, K, V, S> {
+ type Item = &'a mut V;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ unsafe { self.map.table.par_iter() }
+ .map(|x| unsafe { &mut x.as_mut().1 })
+ .drive_unindexed(consumer)
+ }
+}
+
+impl<K: Eq + Hash, V: fmt::Debug, S: BuildHasher> fmt::Debug for ParValuesMut<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.values().fmt(f)
+ }
+}
+
+/// Parallel iterator over entries of a consumed map.
+///
+/// This iterator is created by the [`into_par_iter`] method on [`HashMap`]
+/// (provided by the [`IntoParallelIterator`] trait).
+/// See its documentation for more.
+///
+/// [`into_par_iter`]: /hashbrown/struct.HashMap.html#method.into_par_iter
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+/// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html
+pub struct IntoParIter<K, V, S> {
+ map: HashMap<K, V, S>,
+}
+
+impl<K: Send, V: Send, S: Send> ParallelIterator for IntoParIter<K, V, S> {
+ type Item = (K, V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.map.table.into_par_iter().drive_unindexed(consumer)
+ }
+}
+
+impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, S: BuildHasher> fmt::Debug for IntoParIter<K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.iter().fmt(f)
+ }
+}
+
+/// Parallel draining iterator over entries of a map.
+///
+/// This iterator is created by the [`par_drain`] method on [`HashMap`].
+/// See its documentation for more.
+///
+/// [`par_drain`]: /hashbrown/struct.HashMap.html#method.par_drain
+/// [`HashMap`]: /hashbrown/struct.HashMap.html
+pub struct ParDrain<'a, K, V, S> {
+ map: &'a mut HashMap<K, V, S>,
+}
+
+impl<K: Send, V: Send, S: Send> ParallelIterator for ParDrain<'_, K, V, S> {
+ type Item = (K, V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.map.table.par_drain().drive_unindexed(consumer)
+ }
+}
+
+impl<K: fmt::Debug + Eq + Hash, V: fmt::Debug, S: BuildHasher> fmt::Debug
+ for ParDrain<'_, K, V, S>
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.map.iter().fmt(f)
+ }
+}
+
+impl<K: Sync, V: Sync, S: Sync> HashMap<K, V, S> {
+ /// Visits (potentially in parallel) immutably borrowed keys in an arbitrary order.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_keys(&self) -> ParKeys<'_, K, V, S> {
+ ParKeys { map: self }
+ }
+
+ /// Visits (potentially in parallel) immutably borrowed values in an arbitrary order.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_values(&self) -> ParValues<'_, K, V, S> {
+ ParValues { map: self }
+ }
+}
+
+impl<K: Send, V: Send, S: Send> HashMap<K, V, S> {
+ /// Visits (potentially in parallel) mutably borrowed values in an arbitrary order.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_values_mut(&mut self) -> ParValuesMut<'_, K, V, S> {
+ ParValuesMut { map: self }
+ }
+
+ /// Consumes (potentially in parallel) all values in an arbitrary order,
+ /// while preserving the map's allocated memory for reuse.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_drain(&mut self) -> ParDrain<'_, K, V, S> {
+ ParDrain { map: self }
+ }
+}
+
+impl<K, V, S> HashMap<K, V, S>
+where
+ K: Eq + Hash + Sync,
+ V: PartialEq + Sync,
+ S: BuildHasher + Sync,
+{
+ /// Returns `true` if the map is equal to another,
+ /// i.e. both maps contain the same keys mapped to the same values.
+ ///
+ /// This method runs in a potentially parallel fashion.
+ pub fn par_eq(&self, other: &Self) -> bool {
+ self.len() == other.len()
+ && self
+ .into_par_iter()
+ .all(|(key, value)| other.get(key).map_or(false, |v| *value == *v))
+ }
+}
+
+impl<K: Send, V: Send, S: Send> IntoParallelIterator for HashMap<K, V, S> {
+ type Item = (K, V);
+ type Iter = IntoParIter<K, V, S>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_par_iter(self) -> Self::Iter {
+ IntoParIter { map: self }
+ }
+}
+
+impl<'a, K: Sync, V: Sync, S: Sync> IntoParallelIterator for &'a HashMap<K, V, S> {
+ type Item = (&'a K, &'a V);
+ type Iter = ParIter<'a, K, V, S>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_par_iter(self) -> Self::Iter {
+ ParIter { map: self }
+ }
+}
+
+impl<'a, K: Send + Sync, V: Send, S: Send> IntoParallelIterator for &'a mut HashMap<K, V, S> {
+ type Item = (&'a K, &'a mut V);
+ type Iter = ParIterMut<'a, K, V, S>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_par_iter(self) -> Self::Iter {
+ ParIterMut { map: self }
+ }
+}
+
+/// Collect (key, value) pairs from a parallel iterator into a
+/// hashmap. If multiple pairs correspond to the same key, then the
+/// ones produced earlier in the parallel iterator will be
+/// overwritten, just as with a sequential iterator.
+impl<K, V, S> FromParallelIterator<(K, V)> for HashMap<K, V, S>
+where
+ K: Eq + Hash + Send,
+ V: Send,
+ S: BuildHasher + Default,
+{
+ fn from_par_iter<P>(par_iter: P) -> Self
+ where
+ P: IntoParallelIterator<Item = (K, V)>,
+ {
+ let mut map = HashMap::default();
+ map.par_extend(par_iter);
+ map
+ }
+}
+
+/// Extend a hash map with items from a parallel iterator.
+impl<K, V, S> ParallelExtend<(K, V)> for HashMap<K, V, S>
+where
+ K: Eq + Hash + Send,
+ V: Send,
+ S: BuildHasher,
+{
+ fn par_extend<I>(&mut self, par_iter: I)
+ where
+ I: IntoParallelIterator<Item = (K, V)>,
+ {
+ extend(self, par_iter);
+ }
+}
+
+/// Extend a hash map with copied items from a parallel iterator.
+impl<'a, K, V, S> ParallelExtend<(&'a K, &'a V)> for HashMap<K, V, S>
+where
+ K: Copy + Eq + Hash + Sync,
+ V: Copy + Sync,
+ S: BuildHasher,
+{
+ fn par_extend<I>(&mut self, par_iter: I)
+ where
+ I: IntoParallelIterator<Item = (&'a K, &'a V)>,
+ {
+ extend(self, par_iter);
+ }
+}
+
+// This is equal to the normal `HashMap` -- no custom advantage.
+fn extend<K, V, S, I>(map: &mut HashMap<K, V, S>, par_iter: I)
+where
+ K: Eq + Hash,
+ S: BuildHasher,
+ I: IntoParallelIterator,
+ HashMap<K, V, S>: Extend<I::Item>,
+{
+ let (list, len) = super::helpers::collect(par_iter);
+
+ // Keys may be already present or show multiple times in the iterator.
+ // Reserve the entire length if the map is empty.
+ // Otherwise reserve half the length (rounded up), so the map
+ // will only resize twice in the worst case.
+ let reserve = if map.is_empty() { len } else { (len + 1) / 2 };
+ map.reserve(reserve);
+ for vec in list {
+ map.extend(vec);
+ }
+}
+
+#[cfg(test)]
+mod test_par_map {
+ use alloc::vec::Vec;
+ use core::hash::{Hash, Hasher};
+ use core::sync::atomic::{AtomicUsize, Ordering};
+
+ use rayon::prelude::*;
+
+ use crate::hash_map::HashMap;
+
+ struct Dropable<'a> {
+ k: usize,
+ counter: &'a AtomicUsize,
+ }
+
+ impl Dropable<'_> {
+ fn new(k: usize, counter: &AtomicUsize) -> Dropable<'_> {
+ counter.fetch_add(1, Ordering::Relaxed);
+
+ Dropable { k, counter }
+ }
+ }
+
+ impl Drop for Dropable<'_> {
+ fn drop(&mut self) {
+ self.counter.fetch_sub(1, Ordering::Relaxed);
+ }
+ }
+
+ impl Clone for Dropable<'_> {
+ fn clone(&self) -> Self {
+ Dropable::new(self.k, self.counter)
+ }
+ }
+
+ impl Hash for Dropable<'_> {
+ fn hash<H>(&self, state: &mut H)
+ where
+ H: Hasher,
+ {
+ self.k.hash(state)
+ }
+ }
+
+ impl PartialEq for Dropable<'_> {
+ fn eq(&self, other: &Self) -> bool {
+ self.k == other.k
+ }
+ }
+
+ impl Eq for Dropable<'_> {}
+
+ #[test]
+ fn test_into_iter_drops() {
+ let key = AtomicUsize::new(0);
+ let value = AtomicUsize::new(0);
+
+ let hm = {
+ let mut hm = HashMap::new();
+
+ assert_eq!(key.load(Ordering::Relaxed), 0);
+ assert_eq!(value.load(Ordering::Relaxed), 0);
+
+ for i in 0..100 {
+ let d1 = Dropable::new(i, &key);
+ let d2 = Dropable::new(i + 100, &value);
+ hm.insert(d1, d2);
+ }
+
+ assert_eq!(key.load(Ordering::Relaxed), 100);
+ assert_eq!(value.load(Ordering::Relaxed), 100);
+
+ hm
+ };
+
+ // By the way, ensure that cloning doesn't screw up the dropping.
+ drop(hm.clone());
+
+ assert_eq!(key.load(Ordering::Relaxed), 100);
+ assert_eq!(value.load(Ordering::Relaxed), 100);
+
+ // Ensure that dropping the iterator does not leak anything.
+ drop(hm.clone().into_par_iter());
+
+ {
+ assert_eq!(key.load(Ordering::Relaxed), 100);
+ assert_eq!(value.load(Ordering::Relaxed), 100);
+
+ // retain only half
+ let _v: Vec<_> = hm
+ .into_par_iter()
+ .filter(|&(ref key, _)| key.k < 50)
+ .collect();
+
+ assert_eq!(key.load(Ordering::Relaxed), 50);
+ assert_eq!(value.load(Ordering::Relaxed), 50);
+ };
+
+ assert_eq!(key.load(Ordering::Relaxed), 0);
+ assert_eq!(value.load(Ordering::Relaxed), 0);
+ }
+
+ #[test]
+ fn test_drain_drops() {
+ let key = AtomicUsize::new(0);
+ let value = AtomicUsize::new(0);
+
+ let mut hm = {
+ let mut hm = HashMap::new();
+
+ assert_eq!(key.load(Ordering::Relaxed), 0);
+ assert_eq!(value.load(Ordering::Relaxed), 0);
+
+ for i in 0..100 {
+ let d1 = Dropable::new(i, &key);
+ let d2 = Dropable::new(i + 100, &value);
+ hm.insert(d1, d2);
+ }
+
+ assert_eq!(key.load(Ordering::Relaxed), 100);
+ assert_eq!(value.load(Ordering::Relaxed), 100);
+
+ hm
+ };
+
+ // By the way, ensure that cloning doesn't screw up the dropping.
+ drop(hm.clone());
+
+ assert_eq!(key.load(Ordering::Relaxed), 100);
+ assert_eq!(value.load(Ordering::Relaxed), 100);
+
+ // Ensure that dropping the drain iterator does not leak anything.
+ drop(hm.clone().par_drain());
+
+ {
+ assert_eq!(key.load(Ordering::Relaxed), 100);
+ assert_eq!(value.load(Ordering::Relaxed), 100);
+
+ // retain only half
+ let _v: Vec<_> = hm.drain().filter(|&(ref key, _)| key.k < 50).collect();
+ assert!(hm.is_empty());
+
+ assert_eq!(key.load(Ordering::Relaxed), 50);
+ assert_eq!(value.load(Ordering::Relaxed), 50);
+ };
+
+ assert_eq!(key.load(Ordering::Relaxed), 0);
+ assert_eq!(value.load(Ordering::Relaxed), 0);
+ }
+
+ #[test]
+ fn test_empty_iter() {
+ let mut m: HashMap<isize, bool> = HashMap::new();
+ assert_eq!(m.par_drain().count(), 0);
+ assert_eq!(m.par_keys().count(), 0);
+ assert_eq!(m.par_values().count(), 0);
+ assert_eq!(m.par_values_mut().count(), 0);
+ assert_eq!(m.par_iter().count(), 0);
+ assert_eq!(m.par_iter_mut().count(), 0);
+ assert_eq!(m.len(), 0);
+ assert!(m.is_empty());
+ assert_eq!(m.into_par_iter().count(), 0);
+ }
+
+ #[test]
+ fn test_iterate() {
+ let mut m = HashMap::with_capacity(4);
+ for i in 0..32 {
+ assert!(m.insert(i, i * 2).is_none());
+ }
+ assert_eq!(m.len(), 32);
+
+ let observed = AtomicUsize::new(0);
+
+ m.par_iter().for_each(|(k, v)| {
+ assert_eq!(*v, *k * 2);
+ observed.fetch_or(1 << *k, Ordering::Relaxed);
+ });
+ assert_eq!(observed.into_inner(), 0xFFFF_FFFF);
+ }
+
+ #[test]
+ fn test_keys() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: HashMap<_, _> = vec.into_par_iter().collect();
+ let keys: Vec<_> = map.par_keys().cloned().collect();
+ assert_eq!(keys.len(), 3);
+ assert!(keys.contains(&1));
+ assert!(keys.contains(&2));
+ assert!(keys.contains(&3));
+ }
+
+ #[test]
+ fn test_values() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: HashMap<_, _> = vec.into_par_iter().collect();
+ let values: Vec<_> = map.par_values().cloned().collect();
+ assert_eq!(values.len(), 3);
+ assert!(values.contains(&'a'));
+ assert!(values.contains(&'b'));
+ assert!(values.contains(&'c'));
+ }
+
+ #[test]
+ fn test_values_mut() {
+ let vec = vec![(1, 1), (2, 2), (3, 3)];
+ let mut map: HashMap<_, _> = vec.into_par_iter().collect();
+ map.par_values_mut().for_each(|value| *value = (*value) * 2);
+ let values: Vec<_> = map.par_values().cloned().collect();
+ assert_eq!(values.len(), 3);
+ assert!(values.contains(&2));
+ assert!(values.contains(&4));
+ assert!(values.contains(&6));
+ }
+
+ #[test]
+ fn test_eq() {
+ let mut m1 = HashMap::new();
+ m1.insert(1, 2);
+ m1.insert(2, 3);
+ m1.insert(3, 4);
+
+ let mut m2 = HashMap::new();
+ m2.insert(1, 2);
+ m2.insert(2, 3);
+
+ assert!(!m1.par_eq(&m2));
+
+ m2.insert(3, 4);
+
+ assert!(m1.par_eq(&m2));
+ }
+
+ #[test]
+ fn test_from_iter() {
+ let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let map: HashMap<_, _> = xs.par_iter().cloned().collect();
+
+ for &(k, v) in &xs {
+ assert_eq!(map.get(&k), Some(&v));
+ }
+ }
+
+ #[test]
+ fn test_extend_ref() {
+ let mut a = HashMap::new();
+ a.insert(1, "one");
+ let mut b = HashMap::new();
+ b.insert(2, "two");
+ b.insert(3, "three");
+
+ a.par_extend(&b);
+
+ assert_eq!(a.len(), 3);
+ assert_eq!(a[&1], "one");
+ assert_eq!(a[&2], "two");
+ assert_eq!(a[&3], "three");
+ }
+}
diff --git a/src/external_trait_impls/rayon/mod.rs b/src/external_trait_impls/rayon/mod.rs
new file mode 100644
index 0000000..99337a1
--- /dev/null
+++ b/src/external_trait_impls/rayon/mod.rs
@@ -0,0 +1,4 @@
+mod helpers;
+pub(crate) mod map;
+pub(crate) mod raw;
+pub(crate) mod set;
diff --git a/src/external_trait_impls/rayon/raw.rs b/src/external_trait_impls/rayon/raw.rs
new file mode 100644
index 0000000..1bd2c17
--- /dev/null
+++ b/src/external_trait_impls/rayon/raw.rs
@@ -0,0 +1,199 @@
+use crate::raw::Bucket;
+use crate::raw::{RawIter, RawIterRange, RawTable};
+use crate::scopeguard::guard;
+use alloc::alloc::dealloc;
+use core::marker::PhantomData;
+use core::mem;
+use core::ptr::NonNull;
+use rayon::iter::{
+ plumbing::{self, Folder, UnindexedConsumer, UnindexedProducer},
+ ParallelIterator,
+};
+
+/// Parallel iterator which returns a raw pointer to every full bucket in the table.
+pub struct RawParIter<T> {
+ iter: RawIterRange<T>,
+}
+
+impl<T> From<RawIter<T>> for RawParIter<T> {
+ fn from(it: RawIter<T>) -> Self {
+ RawParIter { iter: it.iter }
+ }
+}
+
+impl<T> ParallelIterator for RawParIter<T> {
+ type Item = Bucket<T>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ let producer = ParIterProducer { iter: self.iter };
+ plumbing::bridge_unindexed(producer, consumer)
+ }
+}
+
+/// Producer which returns a `Bucket<T>` for every element.
+struct ParIterProducer<T> {
+ iter: RawIterRange<T>,
+}
+
+impl<T> UnindexedProducer for ParIterProducer<T> {
+ type Item = Bucket<T>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn split(self) -> (Self, Option<Self>) {
+ let (left, right) = self.iter.split();
+ let left = ParIterProducer { iter: left };
+ let right = right.map(|right| ParIterProducer { iter: right });
+ (left, right)
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn fold_with<F>(self, folder: F) -> F
+ where
+ F: Folder<Self::Item>,
+ {
+ folder.consume_iter(self.iter)
+ }
+}
+
+/// Parallel iterator which consumes a table and returns elements.
+pub struct RawIntoParIter<T> {
+ table: RawTable<T>,
+}
+
+impl<T: Send> ParallelIterator for RawIntoParIter<T> {
+ type Item = T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ let iter = unsafe { self.table.iter().iter };
+ let _guard = guard(self.table.into_alloc(), |alloc| {
+ if let Some((ptr, layout)) = *alloc {
+ unsafe {
+ dealloc(ptr.as_ptr(), layout);
+ }
+ }
+ });
+ let producer = ParDrainProducer { iter };
+ plumbing::bridge_unindexed(producer, consumer)
+ }
+}
+
+/// Parallel iterator which consumes elements without freeing the table storage.
+pub struct RawParDrain<'a, T> {
+ // We don't use a &'a mut RawTable<T> because we want RawParDrain to be
+ // covariant over T.
+ table: NonNull<RawTable<T>>,
+ marker: PhantomData<&'a RawTable<T>>,
+}
+
+unsafe impl<T> Send for RawParDrain<'_, T> {}
+
+impl<T: Send> ParallelIterator for RawParDrain<'_, T> {
+ type Item = T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ let _guard = guard(self.table, |table| unsafe {
+ table.as_mut().clear_no_drop()
+ });
+ let iter = unsafe { self.table.as_ref().iter().iter };
+ mem::forget(self);
+ let producer = ParDrainProducer { iter };
+ plumbing::bridge_unindexed(producer, consumer)
+ }
+}
+
+impl<T> Drop for RawParDrain<'_, T> {
+ fn drop(&mut self) {
+ // If drive_unindexed is not called then simply clear the table.
+ unsafe { self.table.as_mut().clear() }
+ }
+}
+
+/// Producer which will consume all elements in the range, even if it is dropped
+/// halfway through.
+struct ParDrainProducer<T> {
+ iter: RawIterRange<T>,
+}
+
+impl<T: Send> UnindexedProducer for ParDrainProducer<T> {
+ type Item = T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn split(self) -> (Self, Option<Self>) {
+ let (left, right) = self.iter.clone().split();
+ mem::forget(self);
+ let left = ParDrainProducer { iter: left };
+ let right = right.map(|right| ParDrainProducer { iter: right });
+ (left, right)
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn fold_with<F>(mut self, mut folder: F) -> F
+ where
+ F: Folder<Self::Item>,
+ {
+ // Make sure to modify the iterator in-place so that any remaining
+ // elements are processed in our Drop impl.
+ while let Some(item) = self.iter.next() {
+ folder = folder.consume(unsafe { item.read() });
+ if folder.full() {
+ return folder;
+ }
+ }
+
+ // If we processed all elements then we don't need to run the drop.
+ mem::forget(self);
+ folder
+ }
+}
+
+impl<T> Drop for ParDrainProducer<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ // Drop all remaining elements
+ if mem::needs_drop::<T>() {
+ while let Some(item) = self.iter.next() {
+ unsafe {
+ item.drop();
+ }
+ }
+ }
+ }
+}
+
+impl<T> RawTable<T> {
+ /// Returns a parallel iterator over the elements in a `RawTable`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn par_iter(&self) -> RawParIter<T> {
+ RawParIter {
+ iter: self.iter().iter,
+ }
+ }
+
+ /// Returns a parallel iterator over the elements in a `RawTable`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_par_iter(self) -> RawIntoParIter<T> {
+ RawIntoParIter { table: self }
+ }
+
+ /// Returns a parallel iterator which consumes all elements of a `RawTable`
+ /// without freeing its memory allocation.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_drain(&mut self) -> RawParDrain<'_, T> {
+ RawParDrain {
+ table: NonNull::from(self),
+ marker: PhantomData,
+ }
+ }
+}
diff --git a/src/external_trait_impls/rayon/set.rs b/src/external_trait_impls/rayon/set.rs
new file mode 100644
index 0000000..53d2660
--- /dev/null
+++ b/src/external_trait_impls/rayon/set.rs
@@ -0,0 +1,646 @@
+//! Rayon extensions for `HashSet`.
+
+use crate::hash_set::HashSet;
+use core::hash::{BuildHasher, Hash};
+use rayon::iter::plumbing::UnindexedConsumer;
+use rayon::iter::{FromParallelIterator, IntoParallelIterator, ParallelExtend, ParallelIterator};
+
+/// Parallel iterator over elements of a consumed set.
+///
+/// This iterator is created by the [`into_par_iter`] method on [`HashSet`]
+/// (provided by the [`IntoParallelIterator`] trait).
+/// See its documentation for more.
+///
+/// [`into_par_iter`]: /hashbrown/struct.HashSet.html#method.into_par_iter
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+/// [`IntoParallelIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelIterator.html
+pub struct IntoParIter<T, S> {
+ set: HashSet<T, S>,
+}
+
+impl<T: Send, S: Send> ParallelIterator for IntoParIter<T, S> {
+ type Item = T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.set
+ .map
+ .into_par_iter()
+ .map(|(k, _)| k)
+ .drive_unindexed(consumer)
+ }
+}
+
+/// Parallel draining iterator over entries of a set.
+///
+/// This iterator is created by the [`par_drain`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`par_drain`]: /hashbrown/struct.HashSet.html#method.par_drain
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+pub struct ParDrain<'a, T, S> {
+ set: &'a mut HashSet<T, S>,
+}
+
+impl<T: Send, S: Send> ParallelIterator for ParDrain<'_, T, S> {
+ type Item = T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.set
+ .map
+ .par_drain()
+ .map(|(k, _)| k)
+ .drive_unindexed(consumer)
+ }
+}
+
+/// Parallel iterator over shared references to elements in a set.
+///
+/// This iterator is created by the [`par_iter`] method on [`HashSet`]
+/// (provided by the [`IntoParallelRefIterator`] trait).
+/// See its documentation for more.
+///
+/// [`par_iter`]: /hashbrown/struct.HashSet.html#method.par_iter
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+/// [`IntoParallelRefIterator`]: https://docs.rs/rayon/1.0/rayon/iter/trait.IntoParallelRefIterator.html
+pub struct ParIter<'a, T, S> {
+ set: &'a HashSet<T, S>,
+}
+
+impl<'a, T: Sync, S: Sync> ParallelIterator for ParIter<'a, T, S> {
+ type Item = &'a T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.set.map.par_keys().drive_unindexed(consumer)
+ }
+}
+
+/// Parallel iterator over shared references to elements in the difference of
+/// sets.
+///
+/// This iterator is created by the [`par_difference`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`par_difference`]: /hashbrown/struct.HashSet.html#method.par_difference
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+pub struct ParDifference<'a, T, S> {
+ a: &'a HashSet<T, S>,
+ b: &'a HashSet<T, S>,
+}
+
+impl<'a, T, S> ParallelIterator for ParDifference<'a, T, S>
+where
+ T: Eq + Hash + Sync,
+ S: BuildHasher + Sync,
+{
+ type Item = &'a T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.a
+ .into_par_iter()
+ .filter(|&x| !self.b.contains(x))
+ .drive_unindexed(consumer)
+ }
+}
+
+/// Parallel iterator over shared references to elements in the symmetric
+/// difference of sets.
+///
+/// This iterator is created by the [`par_symmetric_difference`] method on
+/// [`HashSet`].
+/// See its documentation for more.
+///
+/// [`par_symmetric_difference`]: /hashbrown/struct.HashSet.html#method.par_symmetric_difference
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+pub struct ParSymmetricDifference<'a, T, S> {
+ a: &'a HashSet<T, S>,
+ b: &'a HashSet<T, S>,
+}
+
+impl<'a, T, S> ParallelIterator for ParSymmetricDifference<'a, T, S>
+where
+ T: Eq + Hash + Sync,
+ S: BuildHasher + Sync,
+{
+ type Item = &'a T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.a
+ .par_difference(self.b)
+ .chain(self.b.par_difference(self.a))
+ .drive_unindexed(consumer)
+ }
+}
+
+/// Parallel iterator over shared references to elements in the intersection of
+/// sets.
+///
+/// This iterator is created by the [`par_intersection`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`par_intersection`]: /hashbrown/struct.HashSet.html#method.par_intersection
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+pub struct ParIntersection<'a, T, S> {
+ a: &'a HashSet<T, S>,
+ b: &'a HashSet<T, S>,
+}
+
+impl<'a, T, S> ParallelIterator for ParIntersection<'a, T, S>
+where
+ T: Eq + Hash + Sync,
+ S: BuildHasher + Sync,
+{
+ type Item = &'a T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.a
+ .into_par_iter()
+ .filter(|&x| self.b.contains(x))
+ .drive_unindexed(consumer)
+ }
+}
+
+/// Parallel iterator over shared references to elements in the union of sets.
+///
+/// This iterator is created by the [`par_union`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`par_union`]: /hashbrown/struct.HashSet.html#method.par_union
+/// [`HashSet`]: /hashbrown/struct.HashSet.html
+pub struct ParUnion<'a, T, S> {
+ a: &'a HashSet<T, S>,
+ b: &'a HashSet<T, S>,
+}
+
+impl<'a, T, S> ParallelIterator for ParUnion<'a, T, S>
+where
+ T: Eq + Hash + Sync,
+ S: BuildHasher + Sync,
+{
+ type Item = &'a T;
+
+ fn drive_unindexed<C>(self, consumer: C) -> C::Result
+ where
+ C: UnindexedConsumer<Self::Item>,
+ {
+ self.a
+ .into_par_iter()
+ .chain(self.b.par_difference(self.a))
+ .drive_unindexed(consumer)
+ }
+}
+
+impl<T, S> HashSet<T, S>
+where
+ T: Eq + Hash + Sync,
+ S: BuildHasher + Sync,
+{
+ /// Visits (potentially in parallel) the values representing the difference,
+ /// i.e. the values that are in `self` but not in `other`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_difference<'a>(&'a self, other: &'a Self) -> ParDifference<'a, T, S> {
+ ParDifference { a: self, b: other }
+ }
+
+ /// Visits (potentially in parallel) the values representing the symmetric
+ /// difference, i.e. the values that are in `self` or in `other` but not in both.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_symmetric_difference<'a>(
+ &'a self,
+ other: &'a Self,
+ ) -> ParSymmetricDifference<'a, T, S> {
+ ParSymmetricDifference { a: self, b: other }
+ }
+
+ /// Visits (potentially in parallel) the values representing the
+ /// intersection, i.e. the values that are both in `self` and `other`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_intersection<'a>(&'a self, other: &'a Self) -> ParIntersection<'a, T, S> {
+ ParIntersection { a: self, b: other }
+ }
+
+ /// Visits (potentially in parallel) the values representing the union,
+ /// i.e. all the values in `self` or `other`, without duplicates.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_union<'a>(&'a self, other: &'a Self) -> ParUnion<'a, T, S> {
+ ParUnion { a: self, b: other }
+ }
+
+ /// Returns `true` if `self` has no elements in common with `other`.
+ /// This is equivalent to checking for an empty intersection.
+ ///
+ /// This method runs in a potentially parallel fashion.
+ pub fn par_is_disjoint(&self, other: &Self) -> bool {
+ self.into_par_iter().all(|x| !other.contains(x))
+ }
+
+ /// Returns `true` if the set is a subset of another,
+ /// i.e. `other` contains at least all the values in `self`.
+ ///
+ /// This method runs in a potentially parallel fashion.
+ pub fn par_is_subset(&self, other: &Self) -> bool {
+ if self.len() <= other.len() {
+ self.into_par_iter().all(|x| other.contains(x))
+ } else {
+ false
+ }
+ }
+
+ /// Returns `true` if the set is a superset of another,
+ /// i.e. `self` contains at least all the values in `other`.
+ ///
+ /// This method runs in a potentially parallel fashion.
+ pub fn par_is_superset(&self, other: &Self) -> bool {
+ other.par_is_subset(self)
+ }
+
+ /// Returns `true` if the set is equal to another,
+ /// i.e. both sets contain the same values.
+ ///
+ /// This method runs in a potentially parallel fashion.
+ pub fn par_eq(&self, other: &Self) -> bool {
+ self.len() == other.len() && self.par_is_subset(other)
+ }
+}
+
+impl<T, S> HashSet<T, S>
+where
+ T: Eq + Hash + Send,
+ S: BuildHasher + Send,
+{
+ /// Consumes (potentially in parallel) all values in an arbitrary order,
+ /// while preserving the set's allocated memory for reuse.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn par_drain(&mut self) -> ParDrain<'_, T, S> {
+ ParDrain { set: self }
+ }
+}
+
+impl<T: Send, S: Send> IntoParallelIterator for HashSet<T, S> {
+ type Item = T;
+ type Iter = IntoParIter<T, S>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_par_iter(self) -> Self::Iter {
+ IntoParIter { set: self }
+ }
+}
+
+impl<'a, T: Sync, S: Sync> IntoParallelIterator for &'a HashSet<T, S> {
+ type Item = &'a T;
+ type Iter = ParIter<'a, T, S>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_par_iter(self) -> Self::Iter {
+ ParIter { set: self }
+ }
+}
+
+/// Collect values from a parallel iterator into a hashset.
+impl<T, S> FromParallelIterator<T> for HashSet<T, S>
+where
+ T: Eq + Hash + Send,
+ S: BuildHasher + Default,
+{
+ fn from_par_iter<P>(par_iter: P) -> Self
+ where
+ P: IntoParallelIterator<Item = T>,
+ {
+ let mut set = HashSet::default();
+ set.par_extend(par_iter);
+ set
+ }
+}
+
+/// Extend a hash set with items from a parallel iterator.
+impl<T, S> ParallelExtend<T> for HashSet<T, S>
+where
+ T: Eq + Hash + Send,
+ S: BuildHasher,
+{
+ fn par_extend<I>(&mut self, par_iter: I)
+ where
+ I: IntoParallelIterator<Item = T>,
+ {
+ extend(self, par_iter);
+ }
+}
+
+/// Extend a hash set with copied items from a parallel iterator.
+impl<'a, T, S> ParallelExtend<&'a T> for HashSet<T, S>
+where
+ T: 'a + Copy + Eq + Hash + Sync,
+ S: BuildHasher,
+{
+ fn par_extend<I>(&mut self, par_iter: I)
+ where
+ I: IntoParallelIterator<Item = &'a T>,
+ {
+ extend(self, par_iter);
+ }
+}
+
+// This is equal to the normal `HashSet` -- no custom advantage.
+fn extend<T, S, I>(set: &mut HashSet<T, S>, par_iter: I)
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+ I: IntoParallelIterator,
+ HashSet<T, S>: Extend<I::Item>,
+{
+ let (list, len) = super::helpers::collect(par_iter);
+
+ // Values may be already present or show multiple times in the iterator.
+ // Reserve the entire length if the set is empty.
+ // Otherwise reserve half the length (rounded up), so the set
+ // will only resize twice in the worst case.
+ let reserve = if set.is_empty() { len } else { (len + 1) / 2 };
+ set.reserve(reserve);
+ for vec in list {
+ set.extend(vec);
+ }
+}
+
+#[cfg(test)]
+mod test_par_set {
+ use alloc::vec::Vec;
+ use core::sync::atomic::{AtomicUsize, Ordering};
+
+ use rayon::prelude::*;
+
+ use crate::hash_set::HashSet;
+
+ #[test]
+ fn test_disjoint() {
+ let mut xs = HashSet::new();
+ let mut ys = HashSet::new();
+ assert!(xs.par_is_disjoint(&ys));
+ assert!(ys.par_is_disjoint(&xs));
+ assert!(xs.insert(5));
+ assert!(ys.insert(11));
+ assert!(xs.par_is_disjoint(&ys));
+ assert!(ys.par_is_disjoint(&xs));
+ assert!(xs.insert(7));
+ assert!(xs.insert(19));
+ assert!(xs.insert(4));
+ assert!(ys.insert(2));
+ assert!(ys.insert(-11));
+ assert!(xs.par_is_disjoint(&ys));
+ assert!(ys.par_is_disjoint(&xs));
+ assert!(ys.insert(7));
+ assert!(!xs.par_is_disjoint(&ys));
+ assert!(!ys.par_is_disjoint(&xs));
+ }
+
+ #[test]
+ fn test_subset_and_superset() {
+ let mut a = HashSet::new();
+ assert!(a.insert(0));
+ assert!(a.insert(5));
+ assert!(a.insert(11));
+ assert!(a.insert(7));
+
+ let mut b = HashSet::new();
+ assert!(b.insert(0));
+ assert!(b.insert(7));
+ assert!(b.insert(19));
+ assert!(b.insert(250));
+ assert!(b.insert(11));
+ assert!(b.insert(200));
+
+ assert!(!a.par_is_subset(&b));
+ assert!(!a.par_is_superset(&b));
+ assert!(!b.par_is_subset(&a));
+ assert!(!b.par_is_superset(&a));
+
+ assert!(b.insert(5));
+
+ assert!(a.par_is_subset(&b));
+ assert!(!a.par_is_superset(&b));
+ assert!(!b.par_is_subset(&a));
+ assert!(b.par_is_superset(&a));
+ }
+
+ #[test]
+ fn test_iterate() {
+ let mut a = HashSet::new();
+ for i in 0..32 {
+ assert!(a.insert(i));
+ }
+ let observed = AtomicUsize::new(0);
+ a.par_iter().for_each(|k| {
+ observed.fetch_or(1 << *k, Ordering::Relaxed);
+ });
+ assert_eq!(observed.into_inner(), 0xFFFF_FFFF);
+ }
+
+ #[test]
+ fn test_intersection() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(11));
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(77));
+ assert!(a.insert(103));
+ assert!(a.insert(5));
+ assert!(a.insert(-5));
+
+ assert!(b.insert(2));
+ assert!(b.insert(11));
+ assert!(b.insert(77));
+ assert!(b.insert(-9));
+ assert!(b.insert(-42));
+ assert!(b.insert(5));
+ assert!(b.insert(3));
+
+ let expected = [3, 5, 11, 77];
+ let i = a
+ .par_intersection(&b)
+ .map(|x| {
+ assert!(expected.contains(x));
+ 1
+ })
+ .sum::<usize>();
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_difference() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(3));
+ assert!(b.insert(9));
+
+ let expected = [1, 5, 11];
+ let i = a
+ .par_difference(&b)
+ .map(|x| {
+ assert!(expected.contains(x));
+ 1
+ })
+ .sum::<usize>();
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_symmetric_difference() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(-2));
+ assert!(b.insert(3));
+ assert!(b.insert(9));
+ assert!(b.insert(14));
+ assert!(b.insert(22));
+
+ let expected = [-2, 1, 5, 11, 14, 22];
+ let i = a
+ .par_symmetric_difference(&b)
+ .map(|x| {
+ assert!(expected.contains(x));
+ 1
+ })
+ .sum::<usize>();
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_union() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+ assert!(a.insert(16));
+ assert!(a.insert(19));
+ assert!(a.insert(24));
+
+ assert!(b.insert(-2));
+ assert!(b.insert(1));
+ assert!(b.insert(5));
+ assert!(b.insert(9));
+ assert!(b.insert(13));
+ assert!(b.insert(19));
+
+ let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
+ let i = a
+ .par_union(&b)
+ .map(|x| {
+ assert!(expected.contains(x));
+ 1
+ })
+ .sum::<usize>();
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_from_iter() {
+ let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9];
+
+ let set: HashSet<_> = xs.par_iter().cloned().collect();
+
+ for x in &xs {
+ assert!(set.contains(x));
+ }
+ }
+
+ #[test]
+ fn test_move_iter() {
+ let hs = {
+ let mut hs = HashSet::new();
+
+ hs.insert('a');
+ hs.insert('b');
+
+ hs
+ };
+
+ let v = hs.into_par_iter().collect::<Vec<char>>();
+ assert!(v == ['a', 'b'] || v == ['b', 'a']);
+ }
+
+ #[test]
+ fn test_eq() {
+ // These constants once happened to expose a bug in insert().
+ // I'm keeping them around to prevent a regression.
+ let mut s1 = HashSet::new();
+
+ s1.insert(1);
+ s1.insert(2);
+ s1.insert(3);
+
+ let mut s2 = HashSet::new();
+
+ s2.insert(1);
+ s2.insert(2);
+
+ assert!(!s1.par_eq(&s2));
+
+ s2.insert(3);
+
+ assert!(s1.par_eq(&s2));
+ }
+
+ #[test]
+ fn test_extend_ref() {
+ let mut a = HashSet::new();
+ a.insert(1);
+
+ a.par_extend(&[2, 3, 4][..]);
+
+ assert_eq!(a.len(), 4);
+ assert!(a.contains(&1));
+ assert!(a.contains(&2));
+ assert!(a.contains(&3));
+ assert!(a.contains(&4));
+
+ let mut b = HashSet::new();
+ b.insert(5);
+ b.insert(6);
+
+ a.par_extend(&b);
+
+ assert_eq!(a.len(), 6);
+ assert!(a.contains(&1));
+ assert!(a.contains(&2));
+ assert!(a.contains(&3));
+ assert!(a.contains(&4));
+ assert!(a.contains(&5));
+ assert!(a.contains(&6));
+ }
+}
diff --git a/src/external_trait_impls/serde.rs b/src/external_trait_impls/serde.rs
new file mode 100644
index 0000000..7816e78
--- /dev/null
+++ b/src/external_trait_impls/serde.rs
@@ -0,0 +1,200 @@
+mod size_hint {
+ use core::cmp;
+
+ /// This presumably exists to prevent denial of service attacks.
+ ///
+ /// Original discussion: https://github.com/serde-rs/serde/issues/1114.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub(super) fn cautious(hint: Option<usize>) -> usize {
+ cmp::min(hint.unwrap_or(0), 4096)
+ }
+}
+
+mod map {
+ use core::fmt;
+ use core::hash::{BuildHasher, Hash};
+ use core::marker::PhantomData;
+ use serde::de::{Deserialize, Deserializer, MapAccess, Visitor};
+ use serde::ser::{Serialize, Serializer};
+
+ use crate::hash_map::HashMap;
+
+ use super::size_hint;
+
+ impl<K, V, H> Serialize for HashMap<K, V, H>
+ where
+ K: Serialize + Eq + Hash,
+ V: Serialize,
+ H: BuildHasher,
+ {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ where
+ S: Serializer,
+ {
+ serializer.collect_map(self)
+ }
+ }
+
+ impl<'de, K, V, S> Deserialize<'de> for HashMap<K, V, S>
+ where
+ K: Deserialize<'de> + Eq + Hash,
+ V: Deserialize<'de>,
+ S: BuildHasher + Default,
+ {
+ fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+ where
+ D: Deserializer<'de>,
+ {
+ struct MapVisitor<K, V, S> {
+ marker: PhantomData<HashMap<K, V, S>>,
+ }
+
+ impl<'de, K, V, S> Visitor<'de> for MapVisitor<K, V, S>
+ where
+ K: Deserialize<'de> + Eq + Hash,
+ V: Deserialize<'de>,
+ S: BuildHasher + Default,
+ {
+ type Value = HashMap<K, V, S>;
+
+ fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ formatter.write_str("a map")
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+ where
+ A: MapAccess<'de>,
+ {
+ let mut values = HashMap::with_capacity_and_hasher(
+ size_hint::cautious(map.size_hint()),
+ S::default(),
+ );
+
+ while let Some((key, value)) = map.next_entry()? {
+ values.insert(key, value);
+ }
+
+ Ok(values)
+ }
+ }
+
+ let visitor = MapVisitor {
+ marker: PhantomData,
+ };
+ deserializer.deserialize_map(visitor)
+ }
+ }
+}
+
+mod set {
+ use core::fmt;
+ use core::hash::{BuildHasher, Hash};
+ use core::marker::PhantomData;
+ use serde::de::{Deserialize, Deserializer, SeqAccess, Visitor};
+ use serde::ser::{Serialize, Serializer};
+
+ use crate::hash_set::HashSet;
+
+ use super::size_hint;
+
+ impl<T, H> Serialize for HashSet<T, H>
+ where
+ T: Serialize + Eq + Hash,
+ H: BuildHasher,
+ {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ where
+ S: Serializer,
+ {
+ serializer.collect_seq(self)
+ }
+ }
+
+ impl<'de, T, S> Deserialize<'de> for HashSet<T, S>
+ where
+ T: Deserialize<'de> + Eq + Hash,
+ S: BuildHasher + Default,
+ {
+ fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+ where
+ D: Deserializer<'de>,
+ {
+ struct SeqVisitor<T, S> {
+ marker: PhantomData<HashSet<T, S>>,
+ }
+
+ impl<'de, T, S> Visitor<'de> for SeqVisitor<T, S>
+ where
+ T: Deserialize<'de> + Eq + Hash,
+ S: BuildHasher + Default,
+ {
+ type Value = HashSet<T, S>;
+
+ fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ formatter.write_str("a sequence")
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+ where
+ A: SeqAccess<'de>,
+ {
+ let mut values = HashSet::with_capacity_and_hasher(
+ size_hint::cautious(seq.size_hint()),
+ S::default(),
+ );
+
+ while let Some(value) = seq.next_element()? {
+ values.insert(value);
+ }
+
+ Ok(values)
+ }
+ }
+
+ let visitor = SeqVisitor {
+ marker: PhantomData,
+ };
+ deserializer.deserialize_seq(visitor)
+ }
+
+ fn deserialize_in_place<D>(deserializer: D, place: &mut Self) -> Result<(), D::Error>
+ where
+ D: Deserializer<'de>,
+ {
+ struct SeqInPlaceVisitor<'a, T, S>(&'a mut HashSet<T, S>);
+
+ impl<'a, 'de, T, S> Visitor<'de> for SeqInPlaceVisitor<'a, T, S>
+ where
+ T: Deserialize<'de> + Eq + Hash,
+ S: BuildHasher + Default,
+ {
+ type Value = ();
+
+ fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+ formatter.write_str("a sequence")
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+ where
+ A: SeqAccess<'de>,
+ {
+ self.0.clear();
+ self.0.reserve(size_hint::cautious(seq.size_hint()));
+
+ while let Some(value) = seq.next_element()? {
+ self.0.insert(value);
+ }
+
+ Ok(())
+ }
+ }
+
+ deserializer.deserialize_seq(SeqInPlaceVisitor(place))
+ }
+ }
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..3aff40a
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,112 @@
+//! This crate is a Rust port of Google's high-performance [SwissTable] hash
+//! map, adapted to make it a drop-in replacement for Rust's standard `HashMap`
+//! and `HashSet` types.
+//!
+//! The original C++ version of [SwissTable] can be found [here], and this
+//! [CppCon talk] gives an overview of how the algorithm works.
+//!
+//! [SwissTable]: https://abseil.io/blog/20180927-swisstables
+//! [here]: https://github.com/abseil/abseil-cpp/blob/master/absl/container/internal/raw_hash_set.h
+//! [CppCon talk]: https://www.youtube.com/watch?v=ncHmEUmJZf4
+
+#![no_std]
+#![cfg_attr(
+ feature = "nightly",
+ feature(test, core_intrinsics, dropck_eyepatch, min_specialization, extend_one)
+)]
+#![allow(
+ clippy::doc_markdown,
+ clippy::module_name_repetitions,
+ clippy::must_use_candidate,
+ clippy::option_if_let_else
+)]
+#![warn(missing_docs)]
+#![warn(rust_2018_idioms)]
+
+#[cfg(test)]
+#[macro_use]
+extern crate std;
+
+#[cfg_attr(test, macro_use)]
+extern crate alloc;
+
+#[cfg(feature = "nightly")]
+#[cfg(doctest)]
+doc_comment::doctest!("../README.md");
+
+#[macro_use]
+mod macros;
+
+#[cfg(feature = "raw")]
+/// Experimental and unsafe `RawTable` API. This module is only available if the
+/// `raw` feature is enabled.
+pub mod raw {
+ // The RawTable API is still experimental and is not properly documented yet.
+ #[allow(missing_docs)]
+ #[path = "mod.rs"]
+ mod inner;
+ pub use inner::*;
+
+ #[cfg(feature = "rayon")]
+ pub mod rayon {
+ pub use crate::external_trait_impls::rayon::raw::*;
+ }
+}
+#[cfg(not(feature = "raw"))]
+mod raw;
+
+mod external_trait_impls;
+mod map;
+#[cfg(feature = "rustc-internal-api")]
+mod rustc_entry;
+mod scopeguard;
+mod set;
+
+pub mod hash_map {
+ //! A hash map implemented with quadratic probing and SIMD lookup.
+ pub use crate::map::*;
+
+ #[cfg(feature = "rustc-internal-api")]
+ pub use crate::rustc_entry::*;
+
+ #[cfg(feature = "rayon")]
+ /// [rayon]-based parallel iterator types for hash maps.
+ /// You will rarely need to interact with it directly unless you have need
+ /// to name one of the iterator types.
+ ///
+ /// [rayon]: https://docs.rs/rayon/1.0/rayon
+ pub mod rayon {
+ pub use crate::external_trait_impls::rayon::map::*;
+ }
+}
+pub mod hash_set {
+ //! A hash set implemented as a `HashMap` where the value is `()`.
+ pub use crate::set::*;
+
+ #[cfg(feature = "rayon")]
+ /// [rayon]-based parallel iterator types for hash sets.
+ /// You will rarely need to interact with it directly unless you have need
+ /// to name one of the iterator types.
+ ///
+ /// [rayon]: https://docs.rs/rayon/1.0/rayon
+ pub mod rayon {
+ pub use crate::external_trait_impls::rayon::set::*;
+ }
+}
+
+pub use crate::map::HashMap;
+pub use crate::set::HashSet;
+
+/// The error type for `try_reserve` methods.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum TryReserveError {
+ /// Error due to the computed capacity exceeding the collection's maximum
+ /// (usually `isize::MAX` bytes).
+ CapacityOverflow,
+
+ /// The memory allocator returned an error
+ AllocError {
+ /// The layout of the allocation request that failed.
+ layout: alloc::alloc::Layout,
+ },
+}
diff --git a/src/macros.rs b/src/macros.rs
new file mode 100644
index 0000000..0279597
--- /dev/null
+++ b/src/macros.rs
@@ -0,0 +1,69 @@
+// See the cfg-if crate.
+macro_rules! cfg_if {
+ // match if/else chains with a final `else`
+ ($(
+ if #[cfg($($meta:meta),*)] { $($it:item)* }
+ ) else * else {
+ $($it2:item)*
+ }) => {
+ cfg_if! {
+ @__items
+ () ;
+ $( ( ($($meta),*) ($($it)*) ), )*
+ ( () ($($it2)*) ),
+ }
+ };
+
+ // match if/else chains lacking a final `else`
+ (
+ if #[cfg($($i_met:meta),*)] { $($i_it:item)* }
+ $(
+ else if #[cfg($($e_met:meta),*)] { $($e_it:item)* }
+ )*
+ ) => {
+ cfg_if! {
+ @__items
+ () ;
+ ( ($($i_met),*) ($($i_it)*) ),
+ $( ( ($($e_met),*) ($($e_it)*) ), )*
+ ( () () ),
+ }
+ };
+
+ // Internal and recursive macro to emit all the items
+ //
+ // Collects all the negated cfgs in a list at the beginning and after the
+ // semicolon is all the remaining items
+ (@__items ($($not:meta,)*) ; ) => {};
+ (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), $($rest:tt)*) => {
+ // Emit all items within one block, applying an approprate #[cfg]. The
+ // #[cfg] will require all `$m` matchers specified and must also negate
+ // all previous matchers.
+ cfg_if! { @__apply cfg(all($($m,)* not(any($($not),*)))), $($it)* }
+
+ // Recurse to emit all other items in `$rest`, and when we do so add all
+ // our `$m` matchers to the list of `$not` matchers as future emissions
+ // will have to negate everything we just matched as well.
+ cfg_if! { @__items ($($not,)* $($m,)*) ; $($rest)* }
+ };
+
+ // Internal macro to Apply a cfg attribute to a list of items
+ (@__apply $m:meta, $($it:item)*) => {
+ $(#[$m] $it)*
+ };
+}
+
+// Helper macro for specialization. This also helps avoid parse errors if the
+// default fn syntax for specialization changes in the future.
+#[cfg(feature = "nightly")]
+macro_rules! default_fn {
+ ($($tt:tt)*) => {
+ default $($tt)*
+ }
+}
+#[cfg(not(feature = "nightly"))]
+macro_rules! default_fn {
+ ($($tt:tt)*) => {
+ $($tt)*
+ }
+}
diff --git a/src/map.rs b/src/map.rs
new file mode 100644
index 0000000..1ccba31
--- /dev/null
+++ b/src/map.rs
@@ -0,0 +1,4524 @@
+use crate::raw::{Bucket, RawDrain, RawIntoIter, RawIter, RawTable};
+use crate::TryReserveError;
+use core::borrow::Borrow;
+use core::fmt::{self, Debug};
+use core::hash::{BuildHasher, Hash, Hasher};
+use core::iter::{FromIterator, FusedIterator};
+use core::marker::PhantomData;
+use core::mem;
+use core::ops::Index;
+
+/// Default hasher for `HashMap`.
+#[cfg(feature = "ahash")]
+pub type DefaultHashBuilder = ahash::RandomState;
+
+/// Dummy default hasher for `HashMap`.
+#[cfg(not(feature = "ahash"))]
+pub enum DefaultHashBuilder {}
+
+/// A hash map implemented with quadratic probing and SIMD lookup.
+///
+/// The default hashing algorithm is currently [`AHash`], though this is
+/// subject to change at any point in the future. This hash function is very
+/// fast for all types of keys, but this algorithm will typically *not* protect
+/// against attacks such as HashDoS.
+///
+/// The hashing algorithm can be replaced on a per-`HashMap` basis using the
+/// [`default`], [`with_hasher`], and [`with_capacity_and_hasher`] methods. Many
+/// alternative algorithms are available on crates.io, such as the [`fnv`] crate.
+///
+/// It is required that the keys implement the [`Eq`] and [`Hash`] traits, although
+/// this can frequently be achieved by using `#[derive(PartialEq, Eq, Hash)]`.
+/// If you implement these yourself, it is important that the following
+/// property holds:
+///
+/// ```text
+/// k1 == k2 -> hash(k1) == hash(k2)
+/// ```
+///
+/// In other words, if two keys are equal, their hashes must be equal.
+///
+/// It is a logic error for a key to be modified in such a way that the key's
+/// hash, as determined by the [`Hash`] trait, or its equality, as determined by
+/// the [`Eq`] trait, changes while it is in the map. This is normally only
+/// possible through [`Cell`], [`RefCell`], global state, I/O, or unsafe code.
+///
+/// It is also a logic error for the [`Hash`] implementation of a key to panic.
+/// This is generally only possible if the trait is implemented manually. If a
+/// panic does occur then the contents of the `HashMap` may become corrupted and
+/// some items may be dropped from the table.
+///
+/// # Examples
+///
+/// ```
+/// use hashbrown::HashMap;
+///
+/// // Type inference lets us omit an explicit type signature (which
+/// // would be `HashMap<String, String>` in this example).
+/// let mut book_reviews = HashMap::new();
+///
+/// // Review some books.
+/// book_reviews.insert(
+/// "Adventures of Huckleberry Finn".to_string(),
+/// "My favorite book.".to_string(),
+/// );
+/// book_reviews.insert(
+/// "Grimms' Fairy Tales".to_string(),
+/// "Masterpiece.".to_string(),
+/// );
+/// book_reviews.insert(
+/// "Pride and Prejudice".to_string(),
+/// "Very enjoyable.".to_string(),
+/// );
+/// book_reviews.insert(
+/// "The Adventures of Sherlock Holmes".to_string(),
+/// "Eye lyked it alot.".to_string(),
+/// );
+///
+/// // Check for a specific one.
+/// // When collections store owned values (String), they can still be
+/// // queried using references (&str).
+/// if !book_reviews.contains_key("Les Misérables") {
+/// println!("We've got {} reviews, but Les Misérables ain't one.",
+/// book_reviews.len());
+/// }
+///
+/// // oops, this review has a lot of spelling mistakes, let's delete it.
+/// book_reviews.remove("The Adventures of Sherlock Holmes");
+///
+/// // Look up the values associated with some keys.
+/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"];
+/// for &book in &to_find {
+/// match book_reviews.get(book) {
+/// Some(review) => println!("{}: {}", book, review),
+/// None => println!("{} is unreviewed.", book)
+/// }
+/// }
+///
+/// // Look up the value for a key (will panic if the key is not found).
+/// println!("Review for Jane: {}", book_reviews["Pride and Prejudice"]);
+///
+/// // Iterate over everything.
+/// for (book, review) in &book_reviews {
+/// println!("{}: \"{}\"", book, review);
+/// }
+/// ```
+///
+/// `HashMap` also implements an [`Entry API`](#method.entry), which allows
+/// for more complex methods of getting, setting, updating and removing keys and
+/// their values:
+///
+/// ```
+/// use hashbrown::HashMap;
+///
+/// // type inference lets us omit an explicit type signature (which
+/// // would be `HashMap<&str, u8>` in this example).
+/// let mut player_stats = HashMap::new();
+///
+/// fn random_stat_buff() -> u8 {
+/// // could actually return some random value here - let's just return
+/// // some fixed value for now
+/// 42
+/// }
+///
+/// // insert a key only if it doesn't already exist
+/// player_stats.entry("health").or_insert(100);
+///
+/// // insert a key using a function that provides a new value only if it
+/// // doesn't already exist
+/// player_stats.entry("defence").or_insert_with(random_stat_buff);
+///
+/// // update a key, guarding against the key possibly not being set
+/// let stat = player_stats.entry("attack").or_insert(100);
+/// *stat += random_stat_buff();
+/// ```
+///
+/// The easiest way to use `HashMap` with a custom key type is to derive [`Eq`] and [`Hash`].
+/// We must also derive [`PartialEq`].
+///
+/// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+/// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+/// [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html
+/// [`RefCell`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html
+/// [`Cell`]: https://doc.rust-lang.org/std/cell/struct.Cell.html
+/// [`default`]: #method.default
+/// [`with_hasher`]: #method.with_hasher
+/// [`with_capacity_and_hasher`]: #method.with_capacity_and_hasher
+/// [`fnv`]: https://crates.io/crates/fnv
+/// [`AHash`]: https://crates.io/crates/ahash
+///
+/// ```
+/// use hashbrown::HashMap;
+///
+/// #[derive(Hash, Eq, PartialEq, Debug)]
+/// struct Viking {
+/// name: String,
+/// country: String,
+/// }
+///
+/// impl Viking {
+/// /// Creates a new Viking.
+/// fn new(name: &str, country: &str) -> Viking {
+/// Viking { name: name.to_string(), country: country.to_string() }
+/// }
+/// }
+///
+/// // Use a HashMap to store the vikings' health points.
+/// let mut vikings = HashMap::new();
+///
+/// vikings.insert(Viking::new("Einar", "Norway"), 25);
+/// vikings.insert(Viking::new("Olaf", "Denmark"), 24);
+/// vikings.insert(Viking::new("Harald", "Iceland"), 12);
+///
+/// // Use derived implementation to print the status of the vikings.
+/// for (viking, health) in &vikings {
+/// println!("{:?} has {} hp", viking, health);
+/// }
+/// ```
+///
+/// A `HashMap` with fixed list of elements can be initialized from an array:
+///
+/// ```
+/// use hashbrown::HashMap;
+///
+/// let timber_resources: HashMap<&str, i32> = [("Norway", 100), ("Denmark", 50), ("Iceland", 10)]
+/// .iter().cloned().collect();
+/// // use the values stored in map
+/// ```
+pub struct HashMap<K, V, S = DefaultHashBuilder> {
+ pub(crate) hash_builder: S,
+ pub(crate) table: RawTable<(K, V)>,
+}
+
+impl<K: Clone, V: Clone, S: Clone> Clone for HashMap<K, V, S> {
+ fn clone(&self) -> Self {
+ HashMap {
+ hash_builder: self.hash_builder.clone(),
+ table: self.table.clone(),
+ }
+ }
+
+ fn clone_from(&mut self, source: &Self) {
+ self.table.clone_from(&source.table);
+
+ // Update hash_builder only if we successfully cloned all elements.
+ self.hash_builder.clone_from(&source.hash_builder);
+ }
+}
+
+#[cfg_attr(feature = "inline-more", inline)]
+pub(crate) fn make_hash<K: Hash + ?Sized>(hash_builder: &impl BuildHasher, val: &K) -> u64 {
+ let mut state = hash_builder.build_hasher();
+ val.hash(&mut state);
+ state.finish()
+}
+
+#[cfg(feature = "ahash")]
+impl<K, V> HashMap<K, V, DefaultHashBuilder> {
+ /// Creates an empty `HashMap`.
+ ///
+ /// The hash map is initially created with a capacity of 0, so it will not allocate until it
+ /// is first inserted into.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// let mut map: HashMap<&str, i32> = HashMap::new();
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn new() -> Self {
+ Self::default()
+ }
+
+ /// Creates an empty `HashMap` with the specified capacity.
+ ///
+ /// The hash map will be able to hold at least `capacity` elements without
+ /// reallocating. If `capacity` is 0, the hash map will not allocate.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// let mut map: HashMap<&str, i32> = HashMap::with_capacity(10);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn with_capacity(capacity: usize) -> Self {
+ Self::with_capacity_and_hasher(capacity, DefaultHashBuilder::default())
+ }
+}
+
+impl<K, V, S> HashMap<K, V, S> {
+ /// Creates an empty `HashMap` which will use the given hash builder to hash
+ /// keys.
+ ///
+ /// The created map has the default initial capacity.
+ ///
+ /// Warning: `hash_builder` is normally randomly generated, and
+ /// is designed to allow HashMaps to be resistant to attacks that
+ /// cause many collisions and very poor performance. Setting it
+ /// manually using this function can expose a DoS attack vector.
+ ///
+ /// The `hash_builder` passed should implement the [`BuildHasher`] trait for
+ /// the HashMap to be useful, see its documentation for details.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::DefaultHashBuilder;
+ ///
+ /// let s = DefaultHashBuilder::default();
+ /// let mut map = HashMap::with_hasher(s);
+ /// map.insert(1, 2);
+ /// ```
+ ///
+ /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub const fn with_hasher(hash_builder: S) -> Self {
+ Self {
+ hash_builder,
+ table: RawTable::new(),
+ }
+ }
+
+ /// Creates an empty `HashMap` with the specified capacity, using `hash_builder`
+ /// to hash the keys.
+ ///
+ /// The hash map will be able to hold at least `capacity` elements without
+ /// reallocating. If `capacity` is 0, the hash map will not allocate.
+ ///
+ /// Warning: `hash_builder` is normally randomly generated, and
+ /// is designed to allow HashMaps to be resistant to attacks that
+ /// cause many collisions and very poor performance. Setting it
+ /// manually using this function can expose a DoS attack vector.
+ ///
+ /// The `hash_builder` passed should implement the [`BuildHasher`] trait for
+ /// the HashMap to be useful, see its documentation for details.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::DefaultHashBuilder;
+ ///
+ /// let s = DefaultHashBuilder::default();
+ /// let mut map = HashMap::with_capacity_and_hasher(10, s);
+ /// map.insert(1, 2);
+ /// ```
+ ///
+ /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self {
+ Self {
+ hash_builder,
+ table: RawTable::with_capacity(capacity),
+ }
+ }
+
+ /// Returns a reference to the map's [`BuildHasher`].
+ ///
+ /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::DefaultHashBuilder;
+ ///
+ /// let hasher = DefaultHashBuilder::default();
+ /// let map: HashMap<i32, i32> = HashMap::with_hasher(hasher);
+ /// let hasher: &DefaultHashBuilder = map.hasher();
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn hasher(&self) -> &S {
+ &self.hash_builder
+ }
+
+ /// Returns the number of elements the map can hold without reallocating.
+ ///
+ /// This number is a lower bound; the `HashMap<K, V>` might be able to hold
+ /// more, but is guaranteed to be able to hold at least this many.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// let map: HashMap<i32, i32> = HashMap::with_capacity(100);
+ /// assert!(map.capacity() >= 100);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn capacity(&self) -> usize {
+ self.table.capacity()
+ }
+
+ /// An iterator visiting all keys in arbitrary order.
+ /// The iterator element type is `&'a K`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for key in map.keys() {
+ /// println!("{}", key);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn keys(&self) -> Keys<'_, K, V> {
+ Keys { inner: self.iter() }
+ }
+
+ /// An iterator visiting all values in arbitrary order.
+ /// The iterator element type is `&'a V`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for val in map.values() {
+ /// println!("{}", val);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn values(&self) -> Values<'_, K, V> {
+ Values { inner: self.iter() }
+ }
+
+ /// An iterator visiting all values mutably in arbitrary order.
+ /// The iterator element type is `&'a mut V`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ ///
+ /// map.insert("a", 1);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for val in map.values_mut() {
+ /// *val = *val + 10;
+ /// }
+ ///
+ /// for val in map.values() {
+ /// println!("{}", val);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> {
+ ValuesMut {
+ inner: self.iter_mut(),
+ }
+ }
+
+ /// An iterator visiting all key-value pairs in arbitrary order.
+ /// The iterator element type is `(&'a K, &'a V)`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for (key, val) in map.iter() {
+ /// println!("key: {} val: {}", key, val);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn iter(&self) -> Iter<'_, K, V> {
+ // Here we tie the lifetime of self to the iter.
+ unsafe {
+ Iter {
+ inner: self.table.iter(),
+ marker: PhantomData,
+ }
+ }
+ }
+
+ /// An iterator visiting all key-value pairs in arbitrary order,
+ /// with mutable references to the values.
+ /// The iterator element type is `(&'a K, &'a mut V)`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// // Update all values
+ /// for (_, val) in map.iter_mut() {
+ /// *val *= 2;
+ /// }
+ ///
+ /// for (key, val) in &map {
+ /// println!("key: {} val: {}", key, val);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn iter_mut(&mut self) -> IterMut<'_, K, V> {
+ // Here we tie the lifetime of self to the iter.
+ unsafe {
+ IterMut {
+ inner: self.table.iter(),
+ marker: PhantomData,
+ }
+ }
+ }
+
+ #[cfg(test)]
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn raw_capacity(&self) -> usize {
+ self.table.buckets()
+ }
+
+ /// Returns the number of elements in the map.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut a = HashMap::new();
+ /// assert_eq!(a.len(), 0);
+ /// a.insert(1, "a");
+ /// assert_eq!(a.len(), 1);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn len(&self) -> usize {
+ self.table.len()
+ }
+
+ /// Returns `true` if the map contains no elements.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut a = HashMap::new();
+ /// assert!(a.is_empty());
+ /// a.insert(1, "a");
+ /// assert!(!a.is_empty());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn is_empty(&self) -> bool {
+ self.len() == 0
+ }
+
+ /// Clears the map, returning all key-value pairs as an iterator. Keeps the
+ /// allocated memory for reuse.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut a = HashMap::new();
+ /// a.insert(1, "a");
+ /// a.insert(2, "b");
+ ///
+ /// for (k, v) in a.drain().take(1) {
+ /// assert!(k == 1 || k == 2);
+ /// assert!(v == "a" || v == "b");
+ /// }
+ ///
+ /// assert!(a.is_empty());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn drain(&mut self) -> Drain<'_, K, V> {
+ Drain {
+ inner: self.table.drain(),
+ }
+ }
+
+ /// Retains only the elements specified by the predicate.
+ ///
+ /// In other words, remove all pairs `(k, v)` such that `f(&k,&mut v)` returns `false`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect();
+ /// map.retain(|&k, _| k % 2 == 0);
+ /// assert_eq!(map.len(), 4);
+ /// ```
+ pub fn retain<F>(&mut self, mut f: F)
+ where
+ F: FnMut(&K, &mut V) -> bool,
+ {
+ // Here we only use `iter` as a temporary, preventing use-after-free
+ unsafe {
+ for item in self.table.iter() {
+ let &mut (ref key, ref mut value) = item.as_mut();
+ if !f(key, value) {
+ self.table.erase(item);
+ }
+ }
+ }
+ }
+
+ /// Drains elements which are true under the given predicate,
+ /// and returns an iterator over the removed items.
+ ///
+ /// In other words, move all pairs `(k, v)` such that `f(&k,&mut v)` returns `true` out
+ /// into another iterator.
+ ///
+ /// When the returned DrainedFilter is dropped, any remaining elements that satisfy
+ /// the predicate are dropped from the table.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x)).collect();
+ /// let drained: HashMap<i32, i32> = map.drain_filter(|k, _v| k % 2 == 0).collect();
+ ///
+ /// let mut evens = drained.keys().cloned().collect::<Vec<_>>();
+ /// let mut odds = map.keys().cloned().collect::<Vec<_>>();
+ /// evens.sort();
+ /// odds.sort();
+ ///
+ /// assert_eq!(evens, vec![0, 2, 4, 6]);
+ /// assert_eq!(odds, vec![1, 3, 5, 7]);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, K, V, F>
+ where
+ F: FnMut(&K, &mut V) -> bool,
+ {
+ DrainFilter {
+ f,
+ inner: DrainFilterInner {
+ iter: unsafe { self.table.iter() },
+ table: &mut self.table,
+ },
+ }
+ }
+
+ /// Clears the map, removing all key-value pairs. Keeps the allocated memory
+ /// for reuse.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut a = HashMap::new();
+ /// a.insert(1, "a");
+ /// a.clear();
+ /// assert!(a.is_empty());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn clear(&mut self) {
+ self.table.clear();
+ }
+}
+
+impl<K, V, S> HashMap<K, V, S>
+where
+ K: Eq + Hash,
+ S: BuildHasher,
+{
+ /// Reserves capacity for at least `additional` more elements to be inserted
+ /// in the `HashMap`. The collection may reserve more space to avoid
+ /// frequent reallocations.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the new allocation size overflows [`usize`].
+ ///
+ /// [`usize`]: https://doc.rust-lang.org/std/primitive.usize.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// let mut map: HashMap<&str, i32> = HashMap::new();
+ /// map.reserve(10);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn reserve(&mut self, additional: usize) {
+ let hash_builder = &self.hash_builder;
+ self.table
+ .reserve(additional, |x| make_hash(hash_builder, &x.0));
+ }
+
+ /// Tries to reserve capacity for at least `additional` more elements to be inserted
+ /// in the given `HashMap<K,V>`. The collection may reserve more space to avoid
+ /// frequent reallocations.
+ ///
+ /// # Errors
+ ///
+ /// If the capacity overflows, or the allocator reports a failure, then an error
+ /// is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// let mut map: HashMap<&str, isize> = HashMap::new();
+ /// map.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
+ let hash_builder = &self.hash_builder;
+ self.table
+ .try_reserve(additional, |x| make_hash(hash_builder, &x.0))
+ }
+
+ /// Shrinks the capacity of the map as much as possible. It will drop
+ /// down as much as possible while maintaining the internal rules
+ /// and possibly leaving some space in accordance with the resize policy.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
+ /// map.insert(1, 2);
+ /// map.insert(3, 4);
+ /// assert!(map.capacity() >= 100);
+ /// map.shrink_to_fit();
+ /// assert!(map.capacity() >= 2);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn shrink_to_fit(&mut self) {
+ let hash_builder = &self.hash_builder;
+ self.table.shrink_to(0, |x| make_hash(hash_builder, &x.0));
+ }
+
+ /// Shrinks the capacity of the map with a lower limit. It will drop
+ /// down no lower than the supplied limit while maintaining the internal rules
+ /// and possibly leaving some space in accordance with the resize policy.
+ ///
+ /// This function does nothing if the current capacity is smaller than the
+ /// supplied minimum capacity.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
+ /// map.insert(1, 2);
+ /// map.insert(3, 4);
+ /// assert!(map.capacity() >= 100);
+ /// map.shrink_to(10);
+ /// assert!(map.capacity() >= 10);
+ /// map.shrink_to(0);
+ /// assert!(map.capacity() >= 2);
+ /// map.shrink_to(10);
+ /// assert!(map.capacity() >= 2);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn shrink_to(&mut self, min_capacity: usize) {
+ let hash_builder = &self.hash_builder;
+ self.table
+ .shrink_to(min_capacity, |x| make_hash(hash_builder, &x.0));
+ }
+
+ /// Gets the given key's corresponding entry in the map for in-place manipulation.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut letters = HashMap::new();
+ ///
+ /// for ch in "a short treatise on fungi".chars() {
+ /// let counter = letters.entry(ch).or_insert(0);
+ /// *counter += 1;
+ /// }
+ ///
+ /// assert_eq!(letters[&'s'], 2);
+ /// assert_eq!(letters[&'t'], 3);
+ /// assert_eq!(letters[&'u'], 1);
+ /// assert_eq!(letters.get(&'y'), None);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn entry(&mut self, key: K) -> Entry<'_, K, V, S> {
+ let hash = make_hash(&self.hash_builder, &key);
+ if let Some(elem) = self.table.find(hash, |q| q.0.eq(&key)) {
+ Entry::Occupied(OccupiedEntry {
+ hash,
+ key: Some(key),
+ elem,
+ table: self,
+ })
+ } else {
+ Entry::Vacant(VacantEntry {
+ hash,
+ key,
+ table: self,
+ })
+ }
+ }
+
+ /// Returns a reference to the value corresponding to the key.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.get(&1), Some(&"a"));
+ /// assert_eq!(map.get(&2), None);
+ /// ```
+ #[inline]
+ pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.get_inner(k) {
+ Some(&(_, ref v)) => Some(v),
+ None => None,
+ }
+ }
+
+ /// Returns the key-value pair corresponding to the supplied key.
+ ///
+ /// The supplied key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
+ /// assert_eq!(map.get_key_value(&2), None);
+ /// ```
+ #[inline]
+ pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.get_inner(k) {
+ Some(&(ref key, ref value)) => Some((key, value)),
+ None => None,
+ }
+ }
+
+ #[inline]
+ fn get_inner<Q: ?Sized>(&self, k: &Q) -> Option<&(K, V)>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ let hash = make_hash(&self.hash_builder, k);
+ self.table.get(hash, |x| k.eq(x.0.borrow()))
+ }
+
+ /// Returns the key-value pair corresponding to the supplied key, with a mutable reference to value.
+ ///
+ /// The supplied key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// let (k, v) = map.get_key_value_mut(&1).unwrap();
+ /// assert_eq!(k, &1);
+ /// assert_eq!(v, &mut "a");
+ /// *v = "b";
+ /// assert_eq!(map.get_key_value_mut(&1), Some((&1, &mut "b")));
+ /// assert_eq!(map.get_key_value_mut(&2), None);
+ /// ```
+ #[inline]
+ pub fn get_key_value_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<(&K, &mut V)>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.get_inner_mut(k) {
+ Some(&mut (ref key, ref mut value)) => Some((key, value)),
+ None => None,
+ }
+ }
+
+ /// Returns `true` if the map contains a value for the specified key.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.contains_key(&1), true);
+ /// assert_eq!(map.contains_key(&2), false);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.get_inner(k).is_some()
+ }
+
+ /// Returns a mutable reference to the value corresponding to the key.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// if let Some(x) = map.get_mut(&1) {
+ /// *x = "b";
+ /// }
+ /// assert_eq!(map[&1], "b");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut V>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.get_inner_mut(k) {
+ Some(&mut (_, ref mut v)) => Some(v),
+ None => None,
+ }
+ }
+
+ #[inline]
+ fn get_inner_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut (K, V)>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ let hash = make_hash(&self.hash_builder, k);
+ self.table.get_mut(hash, |x| k.eq(x.0.borrow()))
+ }
+
+ /// Inserts a key-value pair into the map.
+ ///
+ /// If the map did not have this key present, [`None`] is returned.
+ ///
+ /// If the map did have this key present, the value is updated, and the old
+ /// value is returned. The key is not updated, though; this matters for
+ /// types that can be `==` without being identical. See the [module-level
+ /// documentation] for more.
+ ///
+ /// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
+ /// [module-level documentation]: index.html#insert-and-complex-keys
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// assert_eq!(map.insert(37, "a"), None);
+ /// assert_eq!(map.is_empty(), false);
+ ///
+ /// map.insert(37, "b");
+ /// assert_eq!(map.insert(37, "c"), Some("b"));
+ /// assert_eq!(map[&37], "c");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(&mut self, k: K, v: V) -> Option<V> {
+ let hash = make_hash(&self.hash_builder, &k);
+ if let Some((_, item)) = self.table.get_mut(hash, |x| k.eq(&x.0)) {
+ Some(mem::replace(item, v))
+ } else {
+ let hash_builder = &self.hash_builder;
+ self.table
+ .insert(hash, (k, v), |x| make_hash(hash_builder, &x.0));
+ None
+ }
+ }
+
+ /// Removes a key from the map, returning the value at the key if the key
+ /// was previously in the map.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.remove(&1), Some("a"));
+ /// assert_eq!(map.remove(&1), None);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<V>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.remove_entry(k) {
+ Some((_, v)) => Some(v),
+ None => None,
+ }
+ }
+
+ /// Removes a key from the map, returning the stored key and value if the
+ /// key was previously in the map.
+ ///
+ /// The key may be any borrowed form of the map's key type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the key type.
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(1, "a");
+ /// assert_eq!(map.remove_entry(&1), Some((1, "a")));
+ /// assert_eq!(map.remove(&1), None);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove_entry<Q: ?Sized>(&mut self, k: &Q) -> Option<(K, V)>
+ where
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ let hash = make_hash(&self.hash_builder, &k);
+ self.table.remove_entry(hash, |x| k.eq(x.0.borrow()))
+ }
+}
+
+impl<K, V, S> HashMap<K, V, S> {
+ /// Creates a raw entry builder for the HashMap.
+ ///
+ /// Raw entries provide the lowest level of control for searching and
+ /// manipulating a map. They must be manually initialized with a hash and
+ /// then manually searched. After this, insertions into a vacant entry
+ /// still require an owned key to be provided.
+ ///
+ /// Raw entries are useful for such exotic situations as:
+ ///
+ /// * Hash memoization
+ /// * Deferring the creation of an owned key until it is known to be required
+ /// * Using a search key that doesn't work with the Borrow trait
+ /// * Using custom comparison logic without newtype wrappers
+ ///
+ /// Because raw entries provide much more low-level control, it's much easier
+ /// to put the HashMap into an inconsistent state which, while memory-safe,
+ /// will cause the map to produce seemingly random results. Higher-level and
+ /// more foolproof APIs like `entry` should be preferred when possible.
+ ///
+ /// In particular, the hash used to initialized the raw entry must still be
+ /// consistent with the hash of the key that is ultimately stored in the entry.
+ /// This is because implementations of HashMap may need to recompute hashes
+ /// when resizing, at which point only the keys are available.
+ ///
+ /// Raw entries give mutable access to the keys. This must not be used
+ /// to modify how the key would compare or hash, as the map will not re-evaluate
+ /// where the key should go, meaning the keys may become "lost" if their
+ /// location does not reflect their state. For instance, if you change a key
+ /// so that the map now contains keys which compare equal, search may start
+ /// acting erratically, with two keys randomly masking each other. Implementations
+ /// are free to assume this doesn't happen (within the limits of memory-safety).
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn raw_entry_mut(&mut self) -> RawEntryBuilderMut<'_, K, V, S> {
+ RawEntryBuilderMut { map: self }
+ }
+
+ /// Creates a raw immutable entry builder for the HashMap.
+ ///
+ /// Raw entries provide the lowest level of control for searching and
+ /// manipulating a map. They must be manually initialized with a hash and
+ /// then manually searched.
+ ///
+ /// This is useful for
+ /// * Hash memoization
+ /// * Using a search key that doesn't work with the Borrow trait
+ /// * Using custom comparison logic without newtype wrappers
+ ///
+ /// Unless you are in such a situation, higher-level and more foolproof APIs like
+ /// `get` should be preferred.
+ ///
+ /// Immutable raw entries have very limited use; you might instead want `raw_entry_mut`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn raw_entry(&self) -> RawEntryBuilder<'_, K, V, S> {
+ RawEntryBuilder { map: self }
+ }
+}
+
+impl<K, V, S> PartialEq for HashMap<K, V, S>
+where
+ K: Eq + Hash,
+ V: PartialEq,
+ S: BuildHasher,
+{
+ fn eq(&self, other: &Self) -> bool {
+ if self.len() != other.len() {
+ return false;
+ }
+
+ self.iter()
+ .all(|(key, value)| other.get(key).map_or(false, |v| *value == *v))
+ }
+}
+
+impl<K, V, S> Eq for HashMap<K, V, S>
+where
+ K: Eq + Hash,
+ V: Eq,
+ S: BuildHasher,
+{
+}
+
+impl<K, V, S> Debug for HashMap<K, V, S>
+where
+ K: Debug,
+ V: Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_map().entries(self.iter()).finish()
+ }
+}
+
+impl<K, V, S> Default for HashMap<K, V, S>
+where
+ S: Default,
+{
+ /// Creates an empty `HashMap<K, V, S>`, with the `Default` value for the hasher.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn default() -> Self {
+ Self::with_hasher(Default::default())
+ }
+}
+
+impl<K, Q: ?Sized, V, S> Index<&Q> for HashMap<K, V, S>
+where
+ K: Eq + Hash + Borrow<Q>,
+ Q: Eq + Hash,
+ S: BuildHasher,
+{
+ type Output = V;
+
+ /// Returns a reference to the value corresponding to the supplied key.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the key is not present in the `HashMap`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn index(&self, key: &Q) -> &V {
+ self.get(key).expect("no entry found for key")
+ }
+}
+
+/// An iterator over the entries of a `HashMap`.
+///
+/// This `struct` is created by the [`iter`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`iter`]: struct.HashMap.html#method.iter
+/// [`HashMap`]: struct.HashMap.html
+pub struct Iter<'a, K, V> {
+ inner: RawIter<(K, V)>,
+ marker: PhantomData<(&'a K, &'a V)>,
+}
+
+// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
+impl<K, V> Clone for Iter<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Iter {
+ inner: self.inner.clone(),
+ marker: PhantomData,
+ }
+ }
+}
+
+impl<K: Debug, V: Debug> fmt::Debug for Iter<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+/// A mutable iterator over the entries of a `HashMap`.
+///
+/// This `struct` is created by the [`iter_mut`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`iter_mut`]: struct.HashMap.html#method.iter_mut
+/// [`HashMap`]: struct.HashMap.html
+pub struct IterMut<'a, K, V> {
+ inner: RawIter<(K, V)>,
+ // To ensure invariance with respect to V
+ marker: PhantomData<(&'a K, &'a mut V)>,
+}
+
+// We override the default Send impl which has K: Sync instead of K: Send. Both
+// are correct, but this one is more general since it allows keys which
+// implement Send but not Sync.
+unsafe impl<K: Send, V: Send> Send for IterMut<'_, K, V> {}
+
+impl<K, V> IterMut<'_, K, V> {
+ /// Returns a iterator of references over the remaining items.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub(super) fn iter(&self) -> Iter<'_, K, V> {
+ Iter {
+ inner: self.inner.clone(),
+ marker: PhantomData,
+ }
+ }
+}
+
+/// An owning iterator over the entries of a `HashMap`.
+///
+/// This `struct` is created by the [`into_iter`] method on [`HashMap`]
+/// (provided by the `IntoIterator` trait). See its documentation for more.
+///
+/// [`into_iter`]: struct.HashMap.html#method.into_iter
+/// [`HashMap`]: struct.HashMap.html
+pub struct IntoIter<K, V> {
+ inner: RawIntoIter<(K, V)>,
+}
+
+impl<K, V> IntoIter<K, V> {
+ /// Returns a iterator of references over the remaining items.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub(super) fn iter(&self) -> Iter<'_, K, V> {
+ Iter {
+ inner: self.inner.iter(),
+ marker: PhantomData,
+ }
+ }
+}
+
+/// An iterator over the keys of a `HashMap`.
+///
+/// This `struct` is created by the [`keys`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`keys`]: struct.HashMap.html#method.keys
+/// [`HashMap`]: struct.HashMap.html
+pub struct Keys<'a, K, V> {
+ inner: Iter<'a, K, V>,
+}
+
+// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
+impl<K, V> Clone for Keys<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Keys {
+ inner: self.inner.clone(),
+ }
+ }
+}
+
+impl<K: Debug, V> fmt::Debug for Keys<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+/// An iterator over the values of a `HashMap`.
+///
+/// This `struct` is created by the [`values`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`values`]: struct.HashMap.html#method.values
+/// [`HashMap`]: struct.HashMap.html
+pub struct Values<'a, K, V> {
+ inner: Iter<'a, K, V>,
+}
+
+// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
+impl<K, V> Clone for Values<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Values {
+ inner: self.inner.clone(),
+ }
+ }
+}
+
+impl<K, V: Debug> fmt::Debug for Values<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+/// A draining iterator over the entries of a `HashMap`.
+///
+/// This `struct` is created by the [`drain`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`drain`]: struct.HashMap.html#method.drain
+/// [`HashMap`]: struct.HashMap.html
+pub struct Drain<'a, K, V> {
+ inner: RawDrain<'a, (K, V)>,
+}
+
+impl<K, V> Drain<'_, K, V> {
+ /// Returns a iterator of references over the remaining items.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub(super) fn iter(&self) -> Iter<'_, K, V> {
+ Iter {
+ inner: self.inner.iter(),
+ marker: PhantomData,
+ }
+ }
+}
+
+/// A draining iterator over entries of a `HashMap` which don't satisfy the predicate `f`.
+///
+/// This `struct` is created by the [`drain_filter`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`drain_filter`]: struct.HashMap.html#method.drain_filter
+/// [`HashMap`]: struct.HashMap.html
+pub struct DrainFilter<'a, K, V, F>
+where
+ F: FnMut(&K, &mut V) -> bool,
+{
+ f: F,
+ inner: DrainFilterInner<'a, K, V>,
+}
+
+impl<'a, K, V, F> Drop for DrainFilter<'a, K, V, F>
+where
+ F: FnMut(&K, &mut V) -> bool,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ while let Some(item) = self.next() {
+ let guard = ConsumeAllOnDrop(self);
+ drop(item);
+ mem::forget(guard);
+ }
+ }
+}
+
+pub(super) struct ConsumeAllOnDrop<'a, T: Iterator>(pub &'a mut T);
+
+impl<T: Iterator> Drop for ConsumeAllOnDrop<'_, T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ self.0.for_each(drop)
+ }
+}
+
+impl<K, V, F> Iterator for DrainFilter<'_, K, V, F>
+where
+ F: FnMut(&K, &mut V) -> bool,
+{
+ type Item = (K, V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<Self::Item> {
+ self.inner.next(&mut self.f)
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ (0, self.inner.iter.size_hint().1)
+ }
+}
+
+impl<K, V, F> FusedIterator for DrainFilter<'_, K, V, F> where F: FnMut(&K, &mut V) -> bool {}
+
+/// Portions of `DrainFilter` shared with `set::DrainFilter`
+pub(super) struct DrainFilterInner<'a, K, V> {
+ pub iter: RawIter<(K, V)>,
+ pub table: &'a mut RawTable<(K, V)>,
+}
+
+impl<K, V> DrainFilterInner<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub(super) fn next<F>(&mut self, f: &mut F) -> Option<(K, V)>
+ where
+ F: FnMut(&K, &mut V) -> bool,
+ {
+ unsafe {
+ while let Some(item) = self.iter.next() {
+ let &mut (ref key, ref mut value) = item.as_mut();
+ if f(key, value) {
+ return Some(self.table.remove(item));
+ }
+ }
+ }
+ None
+ }
+}
+
+/// A mutable iterator over the values of a `HashMap`.
+///
+/// This `struct` is created by the [`values_mut`] method on [`HashMap`]. See its
+/// documentation for more.
+///
+/// [`values_mut`]: struct.HashMap.html#method.values_mut
+/// [`HashMap`]: struct.HashMap.html
+pub struct ValuesMut<'a, K, V> {
+ inner: IterMut<'a, K, V>,
+}
+
+/// A builder for computing where in a [`HashMap`] a key-value pair would be stored.
+///
+/// See the [`HashMap::raw_entry_mut`] docs for usage examples.
+///
+/// [`HashMap::raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut
+pub struct RawEntryBuilderMut<'a, K, V, S> {
+ map: &'a mut HashMap<K, V, S>,
+}
+
+/// A view into a single entry in a map, which may either be vacant or occupied.
+///
+/// This is a lower-level version of [`Entry`].
+///
+/// This `enum` is constructed through the [`raw_entry_mut`] method on [`HashMap`],
+/// then calling one of the methods of that [`RawEntryBuilderMut`].
+///
+/// [`HashMap`]: struct.HashMap.html
+/// [`Entry`]: enum.Entry.html
+/// [`raw_entry_mut`]: struct.HashMap.html#method.raw_entry_mut
+/// [`RawEntryBuilderMut`]: struct.RawEntryBuilderMut.html
+pub enum RawEntryMut<'a, K, V, S> {
+ /// An occupied entry.
+ Occupied(RawOccupiedEntryMut<'a, K, V, S>),
+ /// A vacant entry.
+ Vacant(RawVacantEntryMut<'a, K, V, S>),
+}
+
+/// A view into an occupied entry in a `HashMap`.
+/// It is part of the [`RawEntryMut`] enum.
+///
+/// [`RawEntryMut`]: enum.RawEntryMut.html
+pub struct RawOccupiedEntryMut<'a, K, V, S> {
+ elem: Bucket<(K, V)>,
+ table: &'a mut RawTable<(K, V)>,
+ hash_builder: &'a S,
+}
+
+unsafe impl<K, V, S> Send for RawOccupiedEntryMut<'_, K, V, S>
+where
+ K: Send,
+ V: Send,
+ S: Sync,
+{
+}
+unsafe impl<K, V, S> Sync for RawOccupiedEntryMut<'_, K, V, S>
+where
+ K: Sync,
+ V: Sync,
+ S: Sync,
+{
+}
+
+/// A view into a vacant entry in a `HashMap`.
+/// It is part of the [`RawEntryMut`] enum.
+///
+/// [`RawEntryMut`]: enum.RawEntryMut.html
+pub struct RawVacantEntryMut<'a, K, V, S> {
+ table: &'a mut RawTable<(K, V)>,
+ hash_builder: &'a S,
+}
+
+/// A builder for computing where in a [`HashMap`] a key-value pair would be stored.
+///
+/// See the [`HashMap::raw_entry`] docs for usage examples.
+///
+/// [`HashMap::raw_entry`]: struct.HashMap.html#method.raw_entry
+pub struct RawEntryBuilder<'a, K, V, S> {
+ map: &'a HashMap<K, V, S>,
+}
+
+impl<'a, K, V, S> RawEntryBuilderMut<'a, K, V, S> {
+ /// Creates a `RawEntryMut` from the given key.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::wrong_self_convention)]
+ pub fn from_key<Q: ?Sized>(self, k: &Q) -> RawEntryMut<'a, K, V, S>
+ where
+ S: BuildHasher,
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ let mut hasher = self.map.hash_builder.build_hasher();
+ k.hash(&mut hasher);
+ self.from_key_hashed_nocheck(hasher.finish(), k)
+ }
+
+ /// Creates a `RawEntryMut` from the given key and its hash.
+ #[inline]
+ #[allow(clippy::wrong_self_convention)]
+ pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> RawEntryMut<'a, K, V, S>
+ where
+ K: Borrow<Q>,
+ Q: Eq,
+ {
+ self.from_hash(hash, |q| q.borrow().eq(k))
+ }
+}
+
+impl<'a, K, V, S> RawEntryBuilderMut<'a, K, V, S> {
+ /// Creates a `RawEntryMut` from the given hash.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::wrong_self_convention)]
+ pub fn from_hash<F>(self, hash: u64, is_match: F) -> RawEntryMut<'a, K, V, S>
+ where
+ for<'b> F: FnMut(&'b K) -> bool,
+ {
+ self.search(hash, is_match)
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn search<F>(self, hash: u64, mut is_match: F) -> RawEntryMut<'a, K, V, S>
+ where
+ for<'b> F: FnMut(&'b K) -> bool,
+ {
+ match self.map.table.find(hash, |(k, _)| is_match(k)) {
+ Some(elem) => RawEntryMut::Occupied(RawOccupiedEntryMut {
+ elem,
+ table: &mut self.map.table,
+ hash_builder: &self.map.hash_builder,
+ }),
+ None => RawEntryMut::Vacant(RawVacantEntryMut {
+ table: &mut self.map.table,
+ hash_builder: &self.map.hash_builder,
+ }),
+ }
+ }
+}
+
+impl<'a, K, V, S> RawEntryBuilder<'a, K, V, S> {
+ /// Access an entry by key.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::wrong_self_convention)]
+ pub fn from_key<Q: ?Sized>(self, k: &Q) -> Option<(&'a K, &'a V)>
+ where
+ S: BuildHasher,
+ K: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ let mut hasher = self.map.hash_builder.build_hasher();
+ k.hash(&mut hasher);
+ self.from_key_hashed_nocheck(hasher.finish(), k)
+ }
+
+ /// Access an entry by a key and its hash.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::wrong_self_convention)]
+ pub fn from_key_hashed_nocheck<Q: ?Sized>(self, hash: u64, k: &Q) -> Option<(&'a K, &'a V)>
+ where
+ K: Borrow<Q>,
+ Q: Eq,
+ {
+ self.from_hash(hash, |q| q.borrow().eq(k))
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn search<F>(self, hash: u64, mut is_match: F) -> Option<(&'a K, &'a V)>
+ where
+ F: FnMut(&K) -> bool,
+ {
+ match self.map.table.get(hash, |(k, _)| is_match(k)) {
+ Some(&(ref key, ref value)) => Some((key, value)),
+ None => None,
+ }
+ }
+
+ /// Access an entry by hash.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::wrong_self_convention)]
+ pub fn from_hash<F>(self, hash: u64, is_match: F) -> Option<(&'a K, &'a V)>
+ where
+ F: FnMut(&K) -> bool,
+ {
+ self.search(hash, is_match)
+ }
+}
+
+impl<'a, K, V, S> RawEntryMut<'a, K, V, S> {
+ /// Sets the value of the entry, and returns a RawOccupiedEntryMut.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// let entry = map.raw_entry_mut().from_key("horseyland").insert("horseyland", 37);
+ ///
+ /// assert_eq!(entry.remove_entry(), ("horseyland", 37));
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(self, key: K, value: V) -> RawOccupiedEntryMut<'a, K, V, S>
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ RawEntryMut::Occupied(mut entry) => {
+ entry.insert(value);
+ entry
+ }
+ RawEntryMut::Vacant(entry) => entry.insert_entry(key, value),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the default if empty, and returns
+ /// mutable references to the key and value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 3);
+ /// assert_eq!(map["poneyland"], 3);
+ ///
+ /// *map.raw_entry_mut().from_key("poneyland").or_insert("poneyland", 10).1 *= 2;
+ /// assert_eq!(map["poneyland"], 6);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert(self, default_key: K, default_val: V) -> (&'a mut K, &'a mut V)
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ RawEntryMut::Occupied(entry) => entry.into_key_value(),
+ RawEntryMut::Vacant(entry) => entry.insert(default_key, default_val),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the result of the default function if empty,
+ /// and returns mutable references to the key and value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, String> = HashMap::new();
+ ///
+ /// map.raw_entry_mut().from_key("poneyland").or_insert_with(|| {
+ /// ("poneyland", "hoho".to_string())
+ /// });
+ ///
+ /// assert_eq!(map["poneyland"], "hoho".to_string());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert_with<F>(self, default: F) -> (&'a mut K, &'a mut V)
+ where
+ F: FnOnce() -> (K, V),
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ RawEntryMut::Occupied(entry) => entry.into_key_value(),
+ RawEntryMut::Vacant(entry) => {
+ let (k, v) = default();
+ entry.insert(k, v)
+ }
+ }
+ }
+
+ /// Provides in-place mutable access to an occupied entry before any
+ /// potential inserts into the map.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// map.raw_entry_mut()
+ /// .from_key("poneyland")
+ /// .and_modify(|_k, v| { *v += 1 })
+ /// .or_insert("poneyland", 42);
+ /// assert_eq!(map["poneyland"], 42);
+ ///
+ /// map.raw_entry_mut()
+ /// .from_key("poneyland")
+ /// .and_modify(|_k, v| { *v += 1 })
+ /// .or_insert("poneyland", 0);
+ /// assert_eq!(map["poneyland"], 43);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn and_modify<F>(self, f: F) -> Self
+ where
+ F: FnOnce(&mut K, &mut V),
+ {
+ match self {
+ RawEntryMut::Occupied(mut entry) => {
+ {
+ let (k, v) = entry.get_key_value_mut();
+ f(k, v);
+ }
+ RawEntryMut::Occupied(entry)
+ }
+ RawEntryMut::Vacant(entry) => RawEntryMut::Vacant(entry),
+ }
+ }
+
+ /// Provides shared access to the key and owned access to the value of
+ /// an occupied entry and allows to replace or remove it based on the
+ /// value of the returned option.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RawEntryMut;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// let entry = map
+ /// .raw_entry_mut()
+ /// .from_key("poneyland")
+ /// .and_replace_entry_with(|_k, _v| panic!());
+ ///
+ /// match entry {
+ /// RawEntryMut::Vacant(_) => {},
+ /// RawEntryMut::Occupied(_) => panic!(),
+ /// }
+ ///
+ /// map.insert("poneyland", 42);
+ ///
+ /// let entry = map
+ /// .raw_entry_mut()
+ /// .from_key("poneyland")
+ /// .and_replace_entry_with(|k, v| {
+ /// assert_eq!(k, &"poneyland");
+ /// assert_eq!(v, 42);
+ /// Some(v + 1)
+ /// });
+ ///
+ /// match entry {
+ /// RawEntryMut::Occupied(e) => {
+ /// assert_eq!(e.key(), &"poneyland");
+ /// assert_eq!(e.get(), &43);
+ /// },
+ /// RawEntryMut::Vacant(_) => panic!(),
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 43);
+ ///
+ /// let entry = map
+ /// .raw_entry_mut()
+ /// .from_key("poneyland")
+ /// .and_replace_entry_with(|_k, _v| None);
+ ///
+ /// match entry {
+ /// RawEntryMut::Vacant(_) => {},
+ /// RawEntryMut::Occupied(_) => panic!(),
+ /// }
+ ///
+ /// assert!(!map.contains_key("poneyland"));
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn and_replace_entry_with<F>(self, f: F) -> Self
+ where
+ F: FnOnce(&K, V) -> Option<V>,
+ {
+ match self {
+ RawEntryMut::Occupied(entry) => entry.replace_entry_with(f),
+ RawEntryMut::Vacant(_) => self,
+ }
+ }
+}
+
+impl<'a, K, V, S> RawOccupiedEntryMut<'a, K, V, S> {
+ /// Gets a reference to the key in the entry.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ unsafe { &self.elem.as_ref().0 }
+ }
+
+ /// Gets a mutable reference to the key in the entry.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key_mut(&mut self) -> &mut K {
+ unsafe { &mut self.elem.as_mut().0 }
+ }
+
+ /// Converts the entry into a mutable reference to the key in the entry
+ /// with a lifetime bound to the map itself.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_key(self) -> &'a mut K {
+ unsafe { &mut self.elem.as_mut().0 }
+ }
+
+ /// Gets a reference to the value in the entry.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get(&self) -> &V {
+ unsafe { &self.elem.as_ref().1 }
+ }
+
+ /// Converts the OccupiedEntry into a mutable reference to the value in the entry
+ /// with a lifetime bound to the map itself.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_mut(self) -> &'a mut V {
+ unsafe { &mut self.elem.as_mut().1 }
+ }
+
+ /// Gets a mutable reference to the value in the entry.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_mut(&mut self) -> &mut V {
+ unsafe { &mut self.elem.as_mut().1 }
+ }
+
+ /// Gets a reference to the key and value in the entry.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_key_value(&mut self) -> (&K, &V) {
+ unsafe {
+ let &(ref key, ref value) = self.elem.as_ref();
+ (key, value)
+ }
+ }
+
+ /// Gets a mutable reference to the key and value in the entry.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_key_value_mut(&mut self) -> (&mut K, &mut V) {
+ unsafe {
+ let &mut (ref mut key, ref mut value) = self.elem.as_mut();
+ (key, value)
+ }
+ }
+
+ /// Converts the OccupiedEntry into a mutable reference to the key and value in the entry
+ /// with a lifetime bound to the map itself.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_key_value(self) -> (&'a mut K, &'a mut V) {
+ unsafe {
+ let &mut (ref mut key, ref mut value) = self.elem.as_mut();
+ (key, value)
+ }
+ }
+
+ /// Sets the value of the entry, and returns the entry's old value.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(&mut self, value: V) -> V {
+ mem::replace(self.get_mut(), value)
+ }
+
+ /// Sets the value of the entry, and returns the entry's old value.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert_key(&mut self, key: K) -> K {
+ mem::replace(self.key_mut(), key)
+ }
+
+ /// Takes the value out of the entry, and returns it.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove(self) -> V {
+ self.remove_entry().1
+ }
+
+ /// Take the ownership of the key and value from the map.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove_entry(self) -> (K, V) {
+ unsafe { self.table.remove(self.elem) }
+ }
+
+ /// Provides shared access to the key and owned access to the value of
+ /// the entry and allows to replace or remove it based on the
+ /// value of the returned option.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace_entry_with<F>(self, f: F) -> RawEntryMut<'a, K, V, S>
+ where
+ F: FnOnce(&K, V) -> Option<V>,
+ {
+ unsafe {
+ let still_occupied = self
+ .table
+ .replace_bucket_with(self.elem.clone(), |(key, value)| {
+ f(&key, value).map(|new_value| (key, new_value))
+ });
+
+ if still_occupied {
+ RawEntryMut::Occupied(self)
+ } else {
+ RawEntryMut::Vacant(RawVacantEntryMut {
+ table: self.table,
+ hash_builder: self.hash_builder,
+ })
+ }
+ }
+ }
+}
+
+impl<'a, K, V, S> RawVacantEntryMut<'a, K, V, S> {
+ /// Sets the value of the entry with the VacantEntry's key,
+ /// and returns a mutable reference to it.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(self, key: K, value: V) -> (&'a mut K, &'a mut V)
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ let mut hasher = self.hash_builder.build_hasher();
+ key.hash(&mut hasher);
+ self.insert_hashed_nocheck(hasher.finish(), key, value)
+ }
+
+ /// Sets the value of the entry with the VacantEntry's key,
+ /// and returns a mutable reference to it.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::shadow_unrelated)]
+ pub fn insert_hashed_nocheck(self, hash: u64, key: K, value: V) -> (&'a mut K, &'a mut V)
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ let hash_builder = self.hash_builder;
+ self.insert_with_hasher(hash, key, value, |k| make_hash(hash_builder, k))
+ }
+
+ /// Set the value of an entry with a custom hasher function.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert_with_hasher<H>(
+ self,
+ hash: u64,
+ key: K,
+ value: V,
+ hasher: H,
+ ) -> (&'a mut K, &'a mut V)
+ where
+ H: Fn(&K) -> u64,
+ {
+ let &mut (ref mut k, ref mut v) = self
+ .table
+ .insert_entry(hash, (key, value), |x| hasher(&x.0));
+ (k, v)
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn insert_entry(self, key: K, value: V) -> RawOccupiedEntryMut<'a, K, V, S>
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ let hash_builder = self.hash_builder;
+ let mut hasher = self.hash_builder.build_hasher();
+ key.hash(&mut hasher);
+
+ let elem = self.table.insert(hasher.finish(), (key, value), |k| {
+ make_hash(hash_builder, &k.0)
+ });
+ RawOccupiedEntryMut {
+ elem,
+ table: self.table,
+ hash_builder: self.hash_builder,
+ }
+ }
+}
+
+impl<K, V, S> Debug for RawEntryBuilderMut<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("RawEntryBuilder").finish()
+ }
+}
+
+impl<K: Debug, V: Debug, S> Debug for RawEntryMut<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match *self {
+ RawEntryMut::Vacant(ref v) => f.debug_tuple("RawEntry").field(v).finish(),
+ RawEntryMut::Occupied(ref o) => f.debug_tuple("RawEntry").field(o).finish(),
+ }
+ }
+}
+
+impl<K: Debug, V: Debug, S> Debug for RawOccupiedEntryMut<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("RawOccupiedEntryMut")
+ .field("key", self.key())
+ .field("value", self.get())
+ .finish()
+ }
+}
+
+impl<K, V, S> Debug for RawVacantEntryMut<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("RawVacantEntryMut").finish()
+ }
+}
+
+impl<K, V, S> Debug for RawEntryBuilder<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("RawEntryBuilder").finish()
+ }
+}
+
+/// A view into a single entry in a map, which may either be vacant or occupied.
+///
+/// This `enum` is constructed from the [`entry`] method on [`HashMap`].
+///
+/// [`HashMap`]: struct.HashMap.html
+/// [`entry`]: struct.HashMap.html#method.entry
+pub enum Entry<'a, K, V, S> {
+ /// An occupied entry.
+ Occupied(OccupiedEntry<'a, K, V, S>),
+
+ /// A vacant entry.
+ Vacant(VacantEntry<'a, K, V, S>),
+}
+
+impl<K: Debug, V: Debug, S> Debug for Entry<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match *self {
+ Entry::Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(),
+ Entry::Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(),
+ }
+ }
+}
+
+/// A view into an occupied entry in a `HashMap`.
+/// It is part of the [`Entry`] enum.
+///
+/// [`Entry`]: enum.Entry.html
+pub struct OccupiedEntry<'a, K, V, S> {
+ hash: u64,
+ key: Option<K>,
+ elem: Bucket<(K, V)>,
+ table: &'a mut HashMap<K, V, S>,
+}
+
+unsafe impl<K, V, S> Send for OccupiedEntry<'_, K, V, S>
+where
+ K: Send,
+ V: Send,
+ S: Send,
+{
+}
+unsafe impl<K, V, S> Sync for OccupiedEntry<'_, K, V, S>
+where
+ K: Sync,
+ V: Sync,
+ S: Sync,
+{
+}
+
+impl<K: Debug, V: Debug, S> Debug for OccupiedEntry<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("OccupiedEntry")
+ .field("key", self.key())
+ .field("value", self.get())
+ .finish()
+ }
+}
+
+/// A view into a vacant entry in a `HashMap`.
+/// It is part of the [`Entry`] enum.
+///
+/// [`Entry`]: enum.Entry.html
+pub struct VacantEntry<'a, K, V, S> {
+ hash: u64,
+ key: K,
+ table: &'a mut HashMap<K, V, S>,
+}
+
+impl<K: Debug, V, S> Debug for VacantEntry<'_, K, V, S> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_tuple("VacantEntry").field(self.key()).finish()
+ }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a HashMap<K, V, S> {
+ type Item = (&'a K, &'a V);
+ type IntoIter = Iter<'a, K, V>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_iter(self) -> Iter<'a, K, V> {
+ self.iter()
+ }
+}
+
+impl<'a, K, V, S> IntoIterator for &'a mut HashMap<K, V, S> {
+ type Item = (&'a K, &'a mut V);
+ type IntoIter = IterMut<'a, K, V>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_iter(self) -> IterMut<'a, K, V> {
+ self.iter_mut()
+ }
+}
+
+impl<K, V, S> IntoIterator for HashMap<K, V, S> {
+ type Item = (K, V);
+ type IntoIter = IntoIter<K, V>;
+
+ /// Creates a consuming iterator, that is, one that moves each key-value
+ /// pair out of the map in arbitrary order. The map cannot be used after
+ /// calling this.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// // Not possible with .iter()
+ /// let vec: Vec<(&str, i32)> = map.into_iter().collect();
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_iter(self) -> IntoIter<K, V> {
+ IntoIter {
+ inner: self.table.into_iter(),
+ }
+ }
+}
+
+impl<'a, K, V> Iterator for Iter<'a, K, V> {
+ type Item = (&'a K, &'a V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<(&'a K, &'a V)> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.inner.next() {
+ Some(x) => unsafe {
+ let r = x.as_ref();
+ Some((&r.0, &r.1))
+ },
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for Iter<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+
+impl<K, V> FusedIterator for Iter<'_, K, V> {}
+
+impl<'a, K, V> Iterator for IterMut<'a, K, V> {
+ type Item = (&'a K, &'a mut V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.inner.next() {
+ Some(x) => unsafe {
+ let r = x.as_mut();
+ Some((&r.0, &mut r.1))
+ },
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for IterMut<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+impl<K, V> FusedIterator for IterMut<'_, K, V> {}
+
+impl<K, V> fmt::Debug for IterMut<'_, K, V>
+where
+ K: fmt::Debug,
+ V: fmt::Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.iter()).finish()
+ }
+}
+
+impl<K, V> Iterator for IntoIter<K, V> {
+ type Item = (K, V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<(K, V)> {
+ self.inner.next()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for IntoIter<K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+impl<K, V> FusedIterator for IntoIter<K, V> {}
+
+impl<K: Debug, V: Debug> fmt::Debug for IntoIter<K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.iter()).finish()
+ }
+}
+
+impl<'a, K, V> Iterator for Keys<'a, K, V> {
+ type Item = &'a K;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a K> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.inner.next() {
+ Some((k, _)) => Some(k),
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for Keys<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+impl<K, V> FusedIterator for Keys<'_, K, V> {}
+
+impl<'a, K, V> Iterator for Values<'a, K, V> {
+ type Item = &'a V;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a V> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.inner.next() {
+ Some((_, v)) => Some(v),
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for Values<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+impl<K, V> FusedIterator for Values<'_, K, V> {}
+
+impl<'a, K, V> Iterator for ValuesMut<'a, K, V> {
+ type Item = &'a mut V;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a mut V> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.inner.next() {
+ Some((_, v)) => Some(v),
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+impl<K, V> FusedIterator for ValuesMut<'_, K, V> {}
+
+impl<K, V> fmt::Debug for ValuesMut<'_, K, V>
+where
+ K: fmt::Debug,
+ V: fmt::Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.inner.iter()).finish()
+ }
+}
+
+impl<'a, K, V> Iterator for Drain<'a, K, V> {
+ type Item = (K, V);
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<(K, V)> {
+ self.inner.next()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.inner.size_hint()
+ }
+}
+impl<K, V> ExactSizeIterator for Drain<'_, K, V> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.inner.len()
+ }
+}
+impl<K, V> FusedIterator for Drain<'_, K, V> {}
+
+impl<K, V> fmt::Debug for Drain<'_, K, V>
+where
+ K: fmt::Debug,
+ V: fmt::Debug,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.iter()).finish()
+ }
+}
+
+impl<'a, K, V, S> Entry<'a, K, V, S> {
+ /// Sets the value of the entry, and returns an OccupiedEntry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// let entry = map.entry("horseyland").insert(37);
+ ///
+ /// assert_eq!(entry.key(), &"horseyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(self, value: V) -> OccupiedEntry<'a, K, V, S>
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ Entry::Occupied(mut entry) => {
+ entry.insert(value);
+ entry
+ }
+ Entry::Vacant(entry) => entry.insert_entry(value),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the default if empty, and returns
+ /// a mutable reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// map.entry("poneyland").or_insert(3);
+ /// assert_eq!(map["poneyland"], 3);
+ ///
+ /// *map.entry("poneyland").or_insert(10) *= 2;
+ /// assert_eq!(map["poneyland"], 6);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert(self, default: V) -> &'a mut V
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ Entry::Occupied(entry) => entry.into_mut(),
+ Entry::Vacant(entry) => entry.insert(default),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the result of the default function if empty,
+ /// and returns a mutable reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, String> = HashMap::new();
+ /// let s = "hoho".to_string();
+ ///
+ /// map.entry("poneyland").or_insert_with(|| s);
+ ///
+ /// assert_eq!(map["poneyland"], "hoho".to_string());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ Entry::Occupied(entry) => entry.into_mut(),
+ Entry::Vacant(entry) => entry.insert(default()),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting, if empty, the result of the default function,
+ /// which takes the key as its argument, and returns a mutable reference to the value in the
+ /// entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, usize> = HashMap::new();
+ ///
+ /// map.entry("poneyland").or_insert_with_key(|key| key.chars().count());
+ ///
+ /// assert_eq!(map["poneyland"], 9);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert_with_key<F: FnOnce(&K) -> V>(self, default: F) -> &'a mut V
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ Entry::Occupied(entry) => entry.into_mut(),
+ Entry::Vacant(entry) => {
+ let value = default(entry.key());
+ entry.insert(value)
+ }
+ }
+ }
+
+ /// Returns a reference to this entry's key.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// assert_eq!(map.entry("poneyland").key(), &"poneyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ match *self {
+ Entry::Occupied(ref entry) => entry.key(),
+ Entry::Vacant(ref entry) => entry.key(),
+ }
+ }
+
+ /// Provides in-place mutable access to an occupied entry before any
+ /// potential inserts into the map.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// map.entry("poneyland")
+ /// .and_modify(|e| { *e += 1 })
+ /// .or_insert(42);
+ /// assert_eq!(map["poneyland"], 42);
+ ///
+ /// map.entry("poneyland")
+ /// .and_modify(|e| { *e += 1 })
+ /// .or_insert(42);
+ /// assert_eq!(map["poneyland"], 43);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn and_modify<F>(self, f: F) -> Self
+ where
+ F: FnOnce(&mut V),
+ {
+ match self {
+ Entry::Occupied(mut entry) => {
+ f(entry.get_mut());
+ Entry::Occupied(entry)
+ }
+ Entry::Vacant(entry) => Entry::Vacant(entry),
+ }
+ }
+
+ /// Provides shared access to the key and owned access to the value of
+ /// an occupied entry and allows to replace or remove it based on the
+ /// value of the returned option.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// let entry = map
+ /// .entry("poneyland")
+ /// .and_replace_entry_with(|_k, _v| panic!());
+ ///
+ /// match entry {
+ /// Entry::Vacant(e) => {
+ /// assert_eq!(e.key(), &"poneyland");
+ /// }
+ /// Entry::Occupied(_) => panic!(),
+ /// }
+ ///
+ /// map.insert("poneyland", 42);
+ ///
+ /// let entry = map
+ /// .entry("poneyland")
+ /// .and_replace_entry_with(|k, v| {
+ /// assert_eq!(k, &"poneyland");
+ /// assert_eq!(v, 42);
+ /// Some(v + 1)
+ /// });
+ ///
+ /// match entry {
+ /// Entry::Occupied(e) => {
+ /// assert_eq!(e.key(), &"poneyland");
+ /// assert_eq!(e.get(), &43);
+ /// }
+ /// Entry::Vacant(_) => panic!(),
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 43);
+ ///
+ /// let entry = map
+ /// .entry("poneyland")
+ /// .and_replace_entry_with(|_k, _v| None);
+ ///
+ /// match entry {
+ /// Entry::Vacant(e) => assert_eq!(e.key(), &"poneyland"),
+ /// Entry::Occupied(_) => panic!(),
+ /// }
+ ///
+ /// assert!(!map.contains_key("poneyland"));
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn and_replace_entry_with<F>(self, f: F) -> Self
+ where
+ F: FnOnce(&K, V) -> Option<V>,
+ {
+ match self {
+ Entry::Occupied(entry) => entry.replace_entry_with(f),
+ Entry::Vacant(_) => self,
+ }
+ }
+}
+
+impl<'a, K, V: Default, S> Entry<'a, K, V, S> {
+ /// Ensures a value is in the entry by inserting the default value if empty,
+ /// and returns a mutable reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, Option<u32>> = HashMap::new();
+ /// map.entry("poneyland").or_default();
+ ///
+ /// assert_eq!(map["poneyland"], None);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_default(self) -> &'a mut V
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ match self {
+ Entry::Occupied(entry) => entry.into_mut(),
+ Entry::Vacant(entry) => entry.insert(Default::default()),
+ }
+ }
+}
+
+impl<'a, K, V, S> OccupiedEntry<'a, K, V, S> {
+ /// Gets a reference to the key in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ /// assert_eq!(map.entry("poneyland").key(), &"poneyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ unsafe { &self.elem.as_ref().0 }
+ }
+
+ /// Take the ownership of the key and value from the map.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ ///
+ /// if let Entry::Occupied(o) = map.entry("poneyland") {
+ /// // We delete the entry from the map.
+ /// o.remove_entry();
+ /// }
+ ///
+ /// assert_eq!(map.contains_key("poneyland"), false);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove_entry(self) -> (K, V) {
+ unsafe { self.table.table.remove(self.elem) }
+ }
+
+ /// Gets a reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ ///
+ /// if let Entry::Occupied(o) = map.entry("poneyland") {
+ /// assert_eq!(o.get(), &12);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get(&self) -> &V {
+ unsafe { &self.elem.as_ref().1 }
+ }
+
+ /// Gets a mutable reference to the value in the entry.
+ ///
+ /// If you need a reference to the `OccupiedEntry` which may outlive the
+ /// destruction of the `Entry` value, see [`into_mut`].
+ ///
+ /// [`into_mut`]: #method.into_mut
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ ///
+ /// assert_eq!(map["poneyland"], 12);
+ /// if let Entry::Occupied(mut o) = map.entry("poneyland") {
+ /// *o.get_mut() += 10;
+ /// assert_eq!(*o.get(), 22);
+ ///
+ /// // We can use the same Entry multiple times.
+ /// *o.get_mut() += 2;
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 24);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_mut(&mut self) -> &mut V {
+ unsafe { &mut self.elem.as_mut().1 }
+ }
+
+ /// Converts the OccupiedEntry into a mutable reference to the value in the entry
+ /// with a lifetime bound to the map itself.
+ ///
+ /// If you need multiple references to the `OccupiedEntry`, see [`get_mut`].
+ ///
+ /// [`get_mut`]: #method.get_mut
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ ///
+ /// assert_eq!(map["poneyland"], 12);
+ /// if let Entry::Occupied(o) = map.entry("poneyland") {
+ /// *o.into_mut() += 10;
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 22);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_mut(self) -> &'a mut V {
+ unsafe { &mut self.elem.as_mut().1 }
+ }
+
+ /// Sets the value of the entry, and returns the entry's old value.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ ///
+ /// if let Entry::Occupied(mut o) = map.entry("poneyland") {
+ /// assert_eq!(o.insert(15), 12);
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 15);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(&mut self, mut value: V) -> V {
+ let old_value = self.get_mut();
+ mem::swap(&mut value, old_value);
+ value
+ }
+
+ /// Takes the value out of the entry, and returns it.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.entry("poneyland").or_insert(12);
+ ///
+ /// if let Entry::Occupied(o) = map.entry("poneyland") {
+ /// assert_eq!(o.remove(), 12);
+ /// }
+ ///
+ /// assert_eq!(map.contains_key("poneyland"), false);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove(self) -> V {
+ self.remove_entry().1
+ }
+
+ /// Replaces the entry, returning the old key and value. The new key in the hash map will be
+ /// the key used to create this entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::hash_map::{Entry, HashMap};
+ /// use std::rc::Rc;
+ ///
+ /// let mut map: HashMap<Rc<String>, u32> = HashMap::new();
+ /// map.insert(Rc::new("Stringthing".to_string()), 15);
+ ///
+ /// let my_key = Rc::new("Stringthing".to_string());
+ ///
+ /// if let Entry::Occupied(entry) = map.entry(my_key) {
+ /// // Also replace the key with a handle to our other key.
+ /// let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16);
+ /// }
+ ///
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace_entry(self, value: V) -> (K, V) {
+ let entry = unsafe { self.elem.as_mut() };
+
+ let old_key = mem::replace(&mut entry.0, self.key.unwrap());
+ let old_value = mem::replace(&mut entry.1, value);
+
+ (old_key, old_value)
+ }
+
+ /// Replaces the key in the hash map with the key used to create this entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::hash_map::{Entry, HashMap};
+ /// use std::rc::Rc;
+ ///
+ /// let mut map: HashMap<Rc<String>, u32> = HashMap::new();
+ /// let mut known_strings: Vec<Rc<String>> = Vec::new();
+ ///
+ /// // Initialise known strings, run program, etc.
+ ///
+ /// reclaim_memory(&mut map, &known_strings);
+ ///
+ /// fn reclaim_memory(map: &mut HashMap<Rc<String>, u32>, known_strings: &[Rc<String>] ) {
+ /// for s in known_strings {
+ /// if let Entry::Occupied(entry) = map.entry(s.clone()) {
+ /// // Replaces the entry's key with our version of it in `known_strings`.
+ /// entry.replace_key();
+ /// }
+ /// }
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace_key(self) -> K {
+ let entry = unsafe { self.elem.as_mut() };
+ mem::replace(&mut entry.0, self.key.unwrap())
+ }
+
+ /// Provides shared access to the key and owned access to the value of
+ /// the entry and allows to replace or remove it based on the
+ /// value of the returned option.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.insert("poneyland", 42);
+ ///
+ /// let entry = match map.entry("poneyland") {
+ /// Entry::Occupied(e) => {
+ /// e.replace_entry_with(|k, v| {
+ /// assert_eq!(k, &"poneyland");
+ /// assert_eq!(v, 42);
+ /// Some(v + 1)
+ /// })
+ /// }
+ /// Entry::Vacant(_) => panic!(),
+ /// };
+ ///
+ /// match entry {
+ /// Entry::Occupied(e) => {
+ /// assert_eq!(e.key(), &"poneyland");
+ /// assert_eq!(e.get(), &43);
+ /// }
+ /// Entry::Vacant(_) => panic!(),
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 43);
+ ///
+ /// let entry = match map.entry("poneyland") {
+ /// Entry::Occupied(e) => e.replace_entry_with(|_k, _v| None),
+ /// Entry::Vacant(_) => panic!(),
+ /// };
+ ///
+ /// match entry {
+ /// Entry::Vacant(e) => {
+ /// assert_eq!(e.key(), &"poneyland");
+ /// }
+ /// Entry::Occupied(_) => panic!(),
+ /// }
+ ///
+ /// assert!(!map.contains_key("poneyland"));
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace_entry_with<F>(self, f: F) -> Entry<'a, K, V, S>
+ where
+ F: FnOnce(&K, V) -> Option<V>,
+ {
+ unsafe {
+ let mut spare_key = None;
+
+ self.table
+ .table
+ .replace_bucket_with(self.elem.clone(), |(key, value)| {
+ if let Some(new_value) = f(&key, value) {
+ Some((key, new_value))
+ } else {
+ spare_key = Some(key);
+ None
+ }
+ });
+
+ if let Some(key) = spare_key {
+ Entry::Vacant(VacantEntry {
+ hash: self.hash,
+ key,
+ table: self.table,
+ })
+ } else {
+ Entry::Occupied(self)
+ }
+ }
+ }
+}
+
+impl<'a, K, V, S> VacantEntry<'a, K, V, S> {
+ /// Gets a reference to the key that would be used when inserting a value
+ /// through the `VacantEntry`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// assert_eq!(map.entry("poneyland").key(), &"poneyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ &self.key
+ }
+
+ /// Take ownership of the key.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// if let Entry::Vacant(v) = map.entry("poneyland") {
+ /// v.into_key();
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_key(self) -> K {
+ self.key
+ }
+
+ /// Sets the value of the entry with the VacantEntry's key,
+ /// and returns a mutable reference to it.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::Entry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// if let Entry::Vacant(o) = map.entry("poneyland") {
+ /// o.insert(37);
+ /// }
+ /// assert_eq!(map["poneyland"], 37);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(self, value: V) -> &'a mut V
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ let hash_builder = &self.table.hash_builder;
+ let table = &mut self.table.table;
+ let entry = table.insert_entry(self.hash, (self.key, value), |x| {
+ make_hash(hash_builder, &x.0)
+ });
+ &mut entry.1
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn insert_entry(self, value: V) -> OccupiedEntry<'a, K, V, S>
+ where
+ K: Hash,
+ S: BuildHasher,
+ {
+ let hash_builder = &self.table.hash_builder;
+ let elem = self.table.table.insert(self.hash, (self.key, value), |x| {
+ make_hash(hash_builder, &x.0)
+ });
+ OccupiedEntry {
+ hash: self.hash,
+ key: None,
+ elem,
+ table: self.table,
+ }
+ }
+}
+
+impl<K, V, S> FromIterator<(K, V)> for HashMap<K, V, S>
+where
+ K: Eq + Hash,
+ S: BuildHasher + Default,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self {
+ let iter = iter.into_iter();
+ let mut map = Self::with_capacity_and_hasher(iter.size_hint().0, S::default());
+ iter.for_each(|(k, v)| {
+ map.insert(k, v);
+ });
+ map
+ }
+}
+
+/// Inserts all new key-values from the iterator and replaces values with existing
+/// keys with new values returned from the iterator.
+impl<K, V, S> Extend<(K, V)> for HashMap<K, V, S>
+where
+ K: Eq + Hash,
+ S: BuildHasher,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T) {
+ // Keys may be already present or show multiple times in the iterator.
+ // Reserve the entire hint lower bound if the map is empty.
+ // Otherwise reserve half the hint (rounded up), so the map
+ // will only resize twice in the worst case.
+ let iter = iter.into_iter();
+ let reserve = if self.is_empty() {
+ iter.size_hint().0
+ } else {
+ (iter.size_hint().0 + 1) / 2
+ };
+ self.reserve(reserve);
+ iter.for_each(move |(k, v)| {
+ self.insert(k, v);
+ });
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_one(&mut self, (k, v): (K, V)) {
+ self.insert(k, v);
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_reserve(&mut self, additional: usize) {
+ // Keys may be already present or show multiple times in the iterator.
+ // Reserve the entire hint lower bound if the map is empty.
+ // Otherwise reserve half the hint (rounded up), so the map
+ // will only resize twice in the worst case.
+ let reserve = if self.is_empty() {
+ additional
+ } else {
+ (additional + 1) / 2
+ };
+ self.reserve(reserve);
+ }
+}
+
+impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap<K, V, S>
+where
+ K: Eq + Hash + Copy,
+ V: Copy,
+ S: BuildHasher,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn extend<T: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: T) {
+ self.extend(iter.into_iter().map(|(&key, &value)| (key, value)));
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_one(&mut self, (k, v): (&'a K, &'a V)) {
+ self.insert(*k, *v);
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_reserve(&mut self, additional: usize) {
+ Extend::<(K, V)>::extend_reserve(self, additional);
+ }
+}
+
+#[allow(dead_code)]
+fn assert_covariance() {
+ fn map_key<'new>(v: HashMap<&'static str, u8>) -> HashMap<&'new str, u8> {
+ v
+ }
+ fn map_val<'new>(v: HashMap<u8, &'static str>) -> HashMap<u8, &'new str> {
+ v
+ }
+ fn iter_key<'a, 'new>(v: Iter<'a, &'static str, u8>) -> Iter<'a, &'new str, u8> {
+ v
+ }
+ fn iter_val<'a, 'new>(v: Iter<'a, u8, &'static str>) -> Iter<'a, u8, &'new str> {
+ v
+ }
+ fn into_iter_key<'new>(v: IntoIter<&'static str, u8>) -> IntoIter<&'new str, u8> {
+ v
+ }
+ fn into_iter_val<'new>(v: IntoIter<u8, &'static str>) -> IntoIter<u8, &'new str> {
+ v
+ }
+ fn keys_key<'a, 'new>(v: Keys<'a, &'static str, u8>) -> Keys<'a, &'new str, u8> {
+ v
+ }
+ fn keys_val<'a, 'new>(v: Keys<'a, u8, &'static str>) -> Keys<'a, u8, &'new str> {
+ v
+ }
+ fn values_key<'a, 'new>(v: Values<'a, &'static str, u8>) -> Values<'a, &'new str, u8> {
+ v
+ }
+ fn values_val<'a, 'new>(v: Values<'a, u8, &'static str>) -> Values<'a, u8, &'new str> {
+ v
+ }
+ fn drain<'new>(
+ d: Drain<'static, &'static str, &'static str>,
+ ) -> Drain<'new, &'new str, &'new str> {
+ d
+ }
+}
+
+#[cfg(test)]
+mod test_map {
+ use super::DefaultHashBuilder;
+ use super::Entry::{Occupied, Vacant};
+ use super::{HashMap, RawEntryMut};
+ use crate::TryReserveError::*;
+ use rand::{rngs::SmallRng, Rng, SeedableRng};
+ use std::cell::RefCell;
+ use std::usize;
+ use std::vec::Vec;
+
+ #[test]
+ fn test_zero_capacities() {
+ type HM = HashMap<i32, i32>;
+
+ let m = HM::new();
+ assert_eq!(m.capacity(), 0);
+
+ let m = HM::default();
+ assert_eq!(m.capacity(), 0);
+
+ let m = HM::with_hasher(DefaultHashBuilder::default());
+ assert_eq!(m.capacity(), 0);
+
+ let m = HM::with_capacity(0);
+ assert_eq!(m.capacity(), 0);
+
+ let m = HM::with_capacity_and_hasher(0, DefaultHashBuilder::default());
+ assert_eq!(m.capacity(), 0);
+
+ let mut m = HM::new();
+ m.insert(1, 1);
+ m.insert(2, 2);
+ m.remove(&1);
+ m.remove(&2);
+ m.shrink_to_fit();
+ assert_eq!(m.capacity(), 0);
+
+ let mut m = HM::new();
+ m.reserve(0);
+ assert_eq!(m.capacity(), 0);
+ }
+
+ #[test]
+ fn test_create_capacity_zero() {
+ let mut m = HashMap::with_capacity(0);
+
+ assert!(m.insert(1, 1).is_none());
+
+ assert!(m.contains_key(&1));
+ assert!(!m.contains_key(&0));
+ }
+
+ #[test]
+ fn test_insert() {
+ let mut m = HashMap::new();
+ assert_eq!(m.len(), 0);
+ assert!(m.insert(1, 2).is_none());
+ assert_eq!(m.len(), 1);
+ assert!(m.insert(2, 4).is_none());
+ assert_eq!(m.len(), 2);
+ assert_eq!(*m.get(&1).unwrap(), 2);
+ assert_eq!(*m.get(&2).unwrap(), 4);
+ }
+
+ #[test]
+ fn test_clone() {
+ let mut m = HashMap::new();
+ assert_eq!(m.len(), 0);
+ assert!(m.insert(1, 2).is_none());
+ assert_eq!(m.len(), 1);
+ assert!(m.insert(2, 4).is_none());
+ assert_eq!(m.len(), 2);
+ let m2 = m.clone();
+ assert_eq!(*m2.get(&1).unwrap(), 2);
+ assert_eq!(*m2.get(&2).unwrap(), 4);
+ assert_eq!(m2.len(), 2);
+ }
+
+ #[test]
+ fn test_clone_from() {
+ let mut m = HashMap::new();
+ let mut m2 = HashMap::new();
+ assert_eq!(m.len(), 0);
+ assert!(m.insert(1, 2).is_none());
+ assert_eq!(m.len(), 1);
+ assert!(m.insert(2, 4).is_none());
+ assert_eq!(m.len(), 2);
+ m2.clone_from(&m);
+ assert_eq!(*m2.get(&1).unwrap(), 2);
+ assert_eq!(*m2.get(&2).unwrap(), 4);
+ assert_eq!(m2.len(), 2);
+ }
+
+ thread_local! { static DROP_VECTOR: RefCell<Vec<i32>> = RefCell::new(Vec::new()) }
+
+ #[derive(Hash, PartialEq, Eq)]
+ struct Droppable {
+ k: usize,
+ }
+
+ impl Droppable {
+ fn new(k: usize) -> Droppable {
+ DROP_VECTOR.with(|slot| {
+ slot.borrow_mut()[k] += 1;
+ });
+
+ Droppable { k }
+ }
+ }
+
+ impl Drop for Droppable {
+ fn drop(&mut self) {
+ DROP_VECTOR.with(|slot| {
+ slot.borrow_mut()[self.k] -= 1;
+ });
+ }
+ }
+
+ impl Clone for Droppable {
+ fn clone(&self) -> Self {
+ Droppable::new(self.k)
+ }
+ }
+
+ #[test]
+ fn test_drops() {
+ DROP_VECTOR.with(|slot| {
+ *slot.borrow_mut() = vec![0; 200];
+ });
+
+ {
+ let mut m = HashMap::new();
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 0);
+ }
+ });
+
+ for i in 0..100 {
+ let d1 = Droppable::new(i);
+ let d2 = Droppable::new(i + 100);
+ m.insert(d1, d2);
+ }
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 1);
+ }
+ });
+
+ for i in 0..50 {
+ let k = Droppable::new(i);
+ let v = m.remove(&k);
+
+ assert!(v.is_some());
+
+ DROP_VECTOR.with(|v| {
+ assert_eq!(v.borrow()[i], 1);
+ assert_eq!(v.borrow()[i + 100], 1);
+ });
+ }
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..50 {
+ assert_eq!(v.borrow()[i], 0);
+ assert_eq!(v.borrow()[i + 100], 0);
+ }
+
+ for i in 50..100 {
+ assert_eq!(v.borrow()[i], 1);
+ assert_eq!(v.borrow()[i + 100], 1);
+ }
+ });
+ }
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 0);
+ }
+ });
+ }
+
+ #[test]
+ fn test_into_iter_drops() {
+ DROP_VECTOR.with(|v| {
+ *v.borrow_mut() = vec![0; 200];
+ });
+
+ let hm = {
+ let mut hm = HashMap::new();
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 0);
+ }
+ });
+
+ for i in 0..100 {
+ let d1 = Droppable::new(i);
+ let d2 = Droppable::new(i + 100);
+ hm.insert(d1, d2);
+ }
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 1);
+ }
+ });
+
+ hm
+ };
+
+ // By the way, ensure that cloning doesn't screw up the dropping.
+ drop(hm.clone());
+
+ {
+ let mut half = hm.into_iter().take(50);
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 1);
+ }
+ });
+
+ for _ in half.by_ref() {}
+
+ DROP_VECTOR.with(|v| {
+ let nk = (0..100).filter(|&i| v.borrow()[i] == 1).count();
+
+ let nv = (0..100).filter(|&i| v.borrow()[i + 100] == 1).count();
+
+ assert_eq!(nk, 50);
+ assert_eq!(nv, 50);
+ });
+ };
+
+ DROP_VECTOR.with(|v| {
+ for i in 0..200 {
+ assert_eq!(v.borrow()[i], 0);
+ }
+ });
+ }
+
+ #[test]
+ fn test_empty_remove() {
+ let mut m: HashMap<i32, bool> = HashMap::new();
+ assert_eq!(m.remove(&0), None);
+ }
+
+ #[test]
+ fn test_empty_entry() {
+ let mut m: HashMap<i32, bool> = HashMap::new();
+ match m.entry(0) {
+ Occupied(_) => panic!(),
+ Vacant(_) => {}
+ }
+ assert!(*m.entry(0).or_insert(true));
+ assert_eq!(m.len(), 1);
+ }
+
+ #[test]
+ fn test_empty_iter() {
+ let mut m: HashMap<i32, bool> = HashMap::new();
+ assert_eq!(m.drain().next(), None);
+ assert_eq!(m.keys().next(), None);
+ assert_eq!(m.values().next(), None);
+ assert_eq!(m.values_mut().next(), None);
+ assert_eq!(m.iter().next(), None);
+ assert_eq!(m.iter_mut().next(), None);
+ assert_eq!(m.len(), 0);
+ assert!(m.is_empty());
+ assert_eq!(m.into_iter().next(), None);
+ }
+
+ #[test]
+ #[cfg_attr(miri, ignore)] // FIXME: takes too long
+ fn test_lots_of_insertions() {
+ let mut m = HashMap::new();
+
+ // Try this a few times to make sure we never screw up the hashmap's
+ // internal state.
+ for _ in 0..10 {
+ assert!(m.is_empty());
+
+ for i in 1..1001 {
+ assert!(m.insert(i, i).is_none());
+
+ for j in 1..=i {
+ let r = m.get(&j);
+ assert_eq!(r, Some(&j));
+ }
+
+ for j in i + 1..1001 {
+ let r = m.get(&j);
+ assert_eq!(r, None);
+ }
+ }
+
+ for i in 1001..2001 {
+ assert!(!m.contains_key(&i));
+ }
+
+ // remove forwards
+ for i in 1..1001 {
+ assert!(m.remove(&i).is_some());
+
+ for j in 1..=i {
+ assert!(!m.contains_key(&j));
+ }
+
+ for j in i + 1..1001 {
+ assert!(m.contains_key(&j));
+ }
+ }
+
+ for i in 1..1001 {
+ assert!(!m.contains_key(&i));
+ }
+
+ for i in 1..1001 {
+ assert!(m.insert(i, i).is_none());
+ }
+
+ // remove backwards
+ for i in (1..1001).rev() {
+ assert!(m.remove(&i).is_some());
+
+ for j in i..1001 {
+ assert!(!m.contains_key(&j));
+ }
+
+ for j in 1..i {
+ assert!(m.contains_key(&j));
+ }
+ }
+ }
+ }
+
+ #[test]
+ fn test_find_mut() {
+ let mut m = HashMap::new();
+ assert!(m.insert(1, 12).is_none());
+ assert!(m.insert(2, 8).is_none());
+ assert!(m.insert(5, 14).is_none());
+ let new = 100;
+ match m.get_mut(&5) {
+ None => panic!(),
+ Some(x) => *x = new,
+ }
+ assert_eq!(m.get(&5), Some(&new));
+ }
+
+ #[test]
+ fn test_insert_overwrite() {
+ let mut m = HashMap::new();
+ assert!(m.insert(1, 2).is_none());
+ assert_eq!(*m.get(&1).unwrap(), 2);
+ assert!(!m.insert(1, 3).is_none());
+ assert_eq!(*m.get(&1).unwrap(), 3);
+ }
+
+ #[test]
+ fn test_insert_conflicts() {
+ let mut m = HashMap::with_capacity(4);
+ assert!(m.insert(1, 2).is_none());
+ assert!(m.insert(5, 3).is_none());
+ assert!(m.insert(9, 4).is_none());
+ assert_eq!(*m.get(&9).unwrap(), 4);
+ assert_eq!(*m.get(&5).unwrap(), 3);
+ assert_eq!(*m.get(&1).unwrap(), 2);
+ }
+
+ #[test]
+ fn test_conflict_remove() {
+ let mut m = HashMap::with_capacity(4);
+ assert!(m.insert(1, 2).is_none());
+ assert_eq!(*m.get(&1).unwrap(), 2);
+ assert!(m.insert(5, 3).is_none());
+ assert_eq!(*m.get(&1).unwrap(), 2);
+ assert_eq!(*m.get(&5).unwrap(), 3);
+ assert!(m.insert(9, 4).is_none());
+ assert_eq!(*m.get(&1).unwrap(), 2);
+ assert_eq!(*m.get(&5).unwrap(), 3);
+ assert_eq!(*m.get(&9).unwrap(), 4);
+ assert!(m.remove(&1).is_some());
+ assert_eq!(*m.get(&9).unwrap(), 4);
+ assert_eq!(*m.get(&5).unwrap(), 3);
+ }
+
+ #[test]
+ fn test_is_empty() {
+ let mut m = HashMap::with_capacity(4);
+ assert!(m.insert(1, 2).is_none());
+ assert!(!m.is_empty());
+ assert!(m.remove(&1).is_some());
+ assert!(m.is_empty());
+ }
+
+ #[test]
+ fn test_remove() {
+ let mut m = HashMap::new();
+ m.insert(1, 2);
+ assert_eq!(m.remove(&1), Some(2));
+ assert_eq!(m.remove(&1), None);
+ }
+
+ #[test]
+ fn test_remove_entry() {
+ let mut m = HashMap::new();
+ m.insert(1, 2);
+ assert_eq!(m.remove_entry(&1), Some((1, 2)));
+ assert_eq!(m.remove(&1), None);
+ }
+
+ #[test]
+ fn test_iterate() {
+ let mut m = HashMap::with_capacity(4);
+ for i in 0..32 {
+ assert!(m.insert(i, i * 2).is_none());
+ }
+ assert_eq!(m.len(), 32);
+
+ let mut observed: u32 = 0;
+
+ for (k, v) in &m {
+ assert_eq!(*v, *k * 2);
+ observed |= 1 << *k;
+ }
+ assert_eq!(observed, 0xFFFF_FFFF);
+ }
+
+ #[test]
+ fn test_keys() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: HashMap<_, _> = vec.into_iter().collect();
+ let keys: Vec<_> = map.keys().cloned().collect();
+ assert_eq!(keys.len(), 3);
+ assert!(keys.contains(&1));
+ assert!(keys.contains(&2));
+ assert!(keys.contains(&3));
+ }
+
+ #[test]
+ fn test_values() {
+ let vec = vec![(1, 'a'), (2, 'b'), (3, 'c')];
+ let map: HashMap<_, _> = vec.into_iter().collect();
+ let values: Vec<_> = map.values().cloned().collect();
+ assert_eq!(values.len(), 3);
+ assert!(values.contains(&'a'));
+ assert!(values.contains(&'b'));
+ assert!(values.contains(&'c'));
+ }
+
+ #[test]
+ fn test_values_mut() {
+ let vec = vec![(1, 1), (2, 2), (3, 3)];
+ let mut map: HashMap<_, _> = vec.into_iter().collect();
+ for value in map.values_mut() {
+ *value = (*value) * 2
+ }
+ let values: Vec<_> = map.values().cloned().collect();
+ assert_eq!(values.len(), 3);
+ assert!(values.contains(&2));
+ assert!(values.contains(&4));
+ assert!(values.contains(&6));
+ }
+
+ #[test]
+ fn test_find() {
+ let mut m = HashMap::new();
+ assert!(m.get(&1).is_none());
+ m.insert(1, 2);
+ match m.get(&1) {
+ None => panic!(),
+ Some(v) => assert_eq!(*v, 2),
+ }
+ }
+
+ #[test]
+ fn test_eq() {
+ let mut m1 = HashMap::new();
+ m1.insert(1, 2);
+ m1.insert(2, 3);
+ m1.insert(3, 4);
+
+ let mut m2 = HashMap::new();
+ m2.insert(1, 2);
+ m2.insert(2, 3);
+
+ assert!(m1 != m2);
+
+ m2.insert(3, 4);
+
+ assert_eq!(m1, m2);
+ }
+
+ #[test]
+ fn test_show() {
+ let mut map = HashMap::new();
+ let empty: HashMap<i32, i32> = HashMap::new();
+
+ map.insert(1, 2);
+ map.insert(3, 4);
+
+ let map_str = format!("{:?}", map);
+
+ assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}");
+ assert_eq!(format!("{:?}", empty), "{}");
+ }
+
+ #[test]
+ fn test_expand() {
+ let mut m = HashMap::new();
+
+ assert_eq!(m.len(), 0);
+ assert!(m.is_empty());
+
+ let mut i = 0;
+ let old_raw_cap = m.raw_capacity();
+ while old_raw_cap == m.raw_capacity() {
+ m.insert(i, i);
+ i += 1;
+ }
+
+ assert_eq!(m.len(), i);
+ assert!(!m.is_empty());
+ }
+
+ #[test]
+ fn test_behavior_resize_policy() {
+ let mut m = HashMap::new();
+
+ assert_eq!(m.len(), 0);
+ assert_eq!(m.raw_capacity(), 1);
+ assert!(m.is_empty());
+
+ m.insert(0, 0);
+ m.remove(&0);
+ assert!(m.is_empty());
+ let initial_raw_cap = m.raw_capacity();
+ m.reserve(initial_raw_cap);
+ let raw_cap = m.raw_capacity();
+
+ assert_eq!(raw_cap, initial_raw_cap * 2);
+
+ let mut i = 0;
+ for _ in 0..raw_cap * 3 / 4 {
+ m.insert(i, i);
+ i += 1;
+ }
+ // three quarters full
+
+ assert_eq!(m.len(), i);
+ assert_eq!(m.raw_capacity(), raw_cap);
+
+ for _ in 0..raw_cap / 4 {
+ m.insert(i, i);
+ i += 1;
+ }
+ // half full
+
+ let new_raw_cap = m.raw_capacity();
+ assert_eq!(new_raw_cap, raw_cap * 2);
+
+ for _ in 0..raw_cap / 2 - 1 {
+ i -= 1;
+ m.remove(&i);
+ assert_eq!(m.raw_capacity(), new_raw_cap);
+ }
+ // A little more than one quarter full.
+ m.shrink_to_fit();
+ assert_eq!(m.raw_capacity(), raw_cap);
+ // again, a little more than half full
+ for _ in 0..raw_cap / 2 {
+ i -= 1;
+ m.remove(&i);
+ }
+ m.shrink_to_fit();
+
+ assert_eq!(m.len(), i);
+ assert!(!m.is_empty());
+ assert_eq!(m.raw_capacity(), initial_raw_cap);
+ }
+
+ #[test]
+ fn test_reserve_shrink_to_fit() {
+ let mut m = HashMap::new();
+ m.insert(0, 0);
+ m.remove(&0);
+ assert!(m.capacity() >= m.len());
+ for i in 0..128 {
+ m.insert(i, i);
+ }
+ m.reserve(256);
+
+ let usable_cap = m.capacity();
+ for i in 128..(128 + 256) {
+ m.insert(i, i);
+ assert_eq!(m.capacity(), usable_cap);
+ }
+
+ for i in 100..(128 + 256) {
+ assert_eq!(m.remove(&i), Some(i));
+ }
+ m.shrink_to_fit();
+
+ assert_eq!(m.len(), 100);
+ assert!(!m.is_empty());
+ assert!(m.capacity() >= m.len());
+
+ for i in 0..100 {
+ assert_eq!(m.remove(&i), Some(i));
+ }
+ m.shrink_to_fit();
+ m.insert(0, 0);
+
+ assert_eq!(m.len(), 1);
+ assert!(m.capacity() >= m.len());
+ assert_eq!(m.remove(&0), Some(0));
+ }
+
+ #[test]
+ fn test_from_iter() {
+ let xs = [(1, 1), (2, 2), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ for &(k, v) in &xs {
+ assert_eq!(map.get(&k), Some(&v));
+ }
+
+ assert_eq!(map.iter().len(), xs.len() - 1);
+ }
+
+ #[test]
+ fn test_size_hint() {
+ let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ let mut iter = map.iter();
+
+ for _ in iter.by_ref().take(3) {}
+
+ assert_eq!(iter.size_hint(), (3, Some(3)));
+ }
+
+ #[test]
+ fn test_iter_len() {
+ let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ let mut iter = map.iter();
+
+ for _ in iter.by_ref().take(3) {}
+
+ assert_eq!(iter.len(), 3);
+ }
+
+ #[test]
+ fn test_mut_size_hint() {
+ let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let mut map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ let mut iter = map.iter_mut();
+
+ for _ in iter.by_ref().take(3) {}
+
+ assert_eq!(iter.size_hint(), (3, Some(3)));
+ }
+
+ #[test]
+ fn test_iter_mut_len() {
+ let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let mut map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ let mut iter = map.iter_mut();
+
+ for _ in iter.by_ref().take(3) {}
+
+ assert_eq!(iter.len(), 3);
+ }
+
+ #[test]
+ fn test_index() {
+ let mut map = HashMap::new();
+
+ map.insert(1, 2);
+ map.insert(2, 1);
+ map.insert(3, 4);
+
+ assert_eq!(map[&2], 1);
+ }
+
+ #[test]
+ #[should_panic]
+ fn test_index_nonexistent() {
+ let mut map = HashMap::new();
+
+ map.insert(1, 2);
+ map.insert(2, 1);
+ map.insert(3, 4);
+
+ map[&4];
+ }
+
+ #[test]
+ fn test_entry() {
+ let xs = [(1, 10), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)];
+
+ let mut map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ // Existing key (insert)
+ match map.entry(1) {
+ Vacant(_) => unreachable!(),
+ Occupied(mut view) => {
+ assert_eq!(view.get(), &10);
+ assert_eq!(view.insert(100), 10);
+ }
+ }
+ assert_eq!(map.get(&1).unwrap(), &100);
+ assert_eq!(map.len(), 6);
+
+ // Existing key (update)
+ match map.entry(2) {
+ Vacant(_) => unreachable!(),
+ Occupied(mut view) => {
+ let v = view.get_mut();
+ let new_v = (*v) * 10;
+ *v = new_v;
+ }
+ }
+ assert_eq!(map.get(&2).unwrap(), &200);
+ assert_eq!(map.len(), 6);
+
+ // Existing key (take)
+ match map.entry(3) {
+ Vacant(_) => unreachable!(),
+ Occupied(view) => {
+ assert_eq!(view.remove(), 30);
+ }
+ }
+ assert_eq!(map.get(&3), None);
+ assert_eq!(map.len(), 5);
+
+ // Inexistent key (insert)
+ match map.entry(10) {
+ Occupied(_) => unreachable!(),
+ Vacant(view) => {
+ assert_eq!(*view.insert(1000), 1000);
+ }
+ }
+ assert_eq!(map.get(&10).unwrap(), &1000);
+ assert_eq!(map.len(), 6);
+ }
+
+ #[test]
+ fn test_entry_take_doesnt_corrupt() {
+ #![allow(deprecated)] //rand
+ // Test for #19292
+ fn check(m: &HashMap<i32, ()>) {
+ for k in m.keys() {
+ assert!(m.contains_key(k), "{} is in keys() but not in the map?", k);
+ }
+ }
+
+ let mut m = HashMap::new();
+
+ let mut rng = {
+ let seed = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
+ SmallRng::from_seed(seed)
+ };
+
+ // Populate the map with some items.
+ for _ in 0..50 {
+ let x = rng.gen_range(-10, 10);
+ m.insert(x, ());
+ }
+
+ for _ in 0..1000 {
+ let x = rng.gen_range(-10, 10);
+ match m.entry(x) {
+ Vacant(_) => {}
+ Occupied(e) => {
+ e.remove();
+ }
+ }
+
+ check(&m);
+ }
+ }
+
+ #[test]
+ fn test_extend_ref() {
+ let mut a = HashMap::new();
+ a.insert(1, "one");
+ let mut b = HashMap::new();
+ b.insert(2, "two");
+ b.insert(3, "three");
+
+ a.extend(&b);
+
+ assert_eq!(a.len(), 3);
+ assert_eq!(a[&1], "one");
+ assert_eq!(a[&2], "two");
+ assert_eq!(a[&3], "three");
+ }
+
+ #[test]
+ fn test_capacity_not_less_than_len() {
+ let mut a = HashMap::new();
+ let mut item = 0;
+
+ for _ in 0..116 {
+ a.insert(item, 0);
+ item += 1;
+ }
+
+ assert!(a.capacity() > a.len());
+
+ let free = a.capacity() - a.len();
+ for _ in 0..free {
+ a.insert(item, 0);
+ item += 1;
+ }
+
+ assert_eq!(a.len(), a.capacity());
+
+ // Insert at capacity should cause allocation.
+ a.insert(item, 0);
+ assert!(a.capacity() > a.len());
+ }
+
+ #[test]
+ fn test_occupied_entry_key() {
+ let mut a = HashMap::new();
+ let key = "hello there";
+ let value = "value goes here";
+ assert!(a.is_empty());
+ a.insert(key.clone(), value.clone());
+ assert_eq!(a.len(), 1);
+ assert_eq!(a[key], value);
+
+ match a.entry(key.clone()) {
+ Vacant(_) => panic!(),
+ Occupied(e) => assert_eq!(key, *e.key()),
+ }
+ assert_eq!(a.len(), 1);
+ assert_eq!(a[key], value);
+ }
+
+ #[test]
+ fn test_vacant_entry_key() {
+ let mut a = HashMap::new();
+ let key = "hello there";
+ let value = "value goes here";
+
+ assert!(a.is_empty());
+ match a.entry(key.clone()) {
+ Occupied(_) => panic!(),
+ Vacant(e) => {
+ assert_eq!(key, *e.key());
+ e.insert(value.clone());
+ }
+ }
+ assert_eq!(a.len(), 1);
+ assert_eq!(a[key], value);
+ }
+
+ #[test]
+ fn test_occupied_entry_replace_entry_with() {
+ let mut a = HashMap::new();
+
+ let key = "a key";
+ let value = "an initial value";
+ let new_value = "a new value";
+
+ let entry = a.entry(key).insert(value).replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, value);
+ Some(new_value)
+ });
+
+ match entry {
+ Occupied(e) => {
+ assert_eq!(e.key(), &key);
+ assert_eq!(e.get(), &new_value);
+ }
+ Vacant(_) => panic!(),
+ }
+
+ assert_eq!(a[key], new_value);
+ assert_eq!(a.len(), 1);
+
+ let entry = match a.entry(key) {
+ Occupied(e) => e.replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, new_value);
+ None
+ }),
+ Vacant(_) => panic!(),
+ };
+
+ match entry {
+ Vacant(e) => assert_eq!(e.key(), &key),
+ Occupied(_) => panic!(),
+ }
+
+ assert!(!a.contains_key(key));
+ assert_eq!(a.len(), 0);
+ }
+
+ #[test]
+ fn test_entry_and_replace_entry_with() {
+ let mut a = HashMap::new();
+
+ let key = "a key";
+ let value = "an initial value";
+ let new_value = "a new value";
+
+ let entry = a.entry(key).and_replace_entry_with(|_, _| panic!());
+
+ match entry {
+ Vacant(e) => assert_eq!(e.key(), &key),
+ Occupied(_) => panic!(),
+ }
+
+ a.insert(key, value);
+
+ let entry = a.entry(key).and_replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, value);
+ Some(new_value)
+ });
+
+ match entry {
+ Occupied(e) => {
+ assert_eq!(e.key(), &key);
+ assert_eq!(e.get(), &new_value);
+ }
+ Vacant(_) => panic!(),
+ }
+
+ assert_eq!(a[key], new_value);
+ assert_eq!(a.len(), 1);
+
+ let entry = a.entry(key).and_replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, new_value);
+ None
+ });
+
+ match entry {
+ Vacant(e) => assert_eq!(e.key(), &key),
+ Occupied(_) => panic!(),
+ }
+
+ assert!(!a.contains_key(key));
+ assert_eq!(a.len(), 0);
+ }
+
+ #[test]
+ fn test_raw_occupied_entry_replace_entry_with() {
+ let mut a = HashMap::new();
+
+ let key = "a key";
+ let value = "an initial value";
+ let new_value = "a new value";
+
+ let entry = a
+ .raw_entry_mut()
+ .from_key(&key)
+ .insert(key, value)
+ .replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, value);
+ Some(new_value)
+ });
+
+ match entry {
+ RawEntryMut::Occupied(e) => {
+ assert_eq!(e.key(), &key);
+ assert_eq!(e.get(), &new_value);
+ }
+ RawEntryMut::Vacant(_) => panic!(),
+ }
+
+ assert_eq!(a[key], new_value);
+ assert_eq!(a.len(), 1);
+
+ let entry = match a.raw_entry_mut().from_key(&key) {
+ RawEntryMut::Occupied(e) => e.replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, new_value);
+ None
+ }),
+ RawEntryMut::Vacant(_) => panic!(),
+ };
+
+ match entry {
+ RawEntryMut::Vacant(_) => {}
+ RawEntryMut::Occupied(_) => panic!(),
+ }
+
+ assert!(!a.contains_key(key));
+ assert_eq!(a.len(), 0);
+ }
+
+ #[test]
+ fn test_raw_entry_and_replace_entry_with() {
+ let mut a = HashMap::new();
+
+ let key = "a key";
+ let value = "an initial value";
+ let new_value = "a new value";
+
+ let entry = a
+ .raw_entry_mut()
+ .from_key(&key)
+ .and_replace_entry_with(|_, _| panic!());
+
+ match entry {
+ RawEntryMut::Vacant(_) => {}
+ RawEntryMut::Occupied(_) => panic!(),
+ }
+
+ a.insert(key, value);
+
+ let entry = a
+ .raw_entry_mut()
+ .from_key(&key)
+ .and_replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, value);
+ Some(new_value)
+ });
+
+ match entry {
+ RawEntryMut::Occupied(e) => {
+ assert_eq!(e.key(), &key);
+ assert_eq!(e.get(), &new_value);
+ }
+ RawEntryMut::Vacant(_) => panic!(),
+ }
+
+ assert_eq!(a[key], new_value);
+ assert_eq!(a.len(), 1);
+
+ let entry = a
+ .raw_entry_mut()
+ .from_key(&key)
+ .and_replace_entry_with(|k, v| {
+ assert_eq!(k, &key);
+ assert_eq!(v, new_value);
+ None
+ });
+
+ match entry {
+ RawEntryMut::Vacant(_) => {}
+ RawEntryMut::Occupied(_) => panic!(),
+ }
+
+ assert!(!a.contains_key(key));
+ assert_eq!(a.len(), 0);
+ }
+
+ #[test]
+ fn test_replace_entry_with_doesnt_corrupt() {
+ #![allow(deprecated)] //rand
+ // Test for #19292
+ fn check(m: &HashMap<i32, ()>) {
+ for k in m.keys() {
+ assert!(m.contains_key(k), "{} is in keys() but not in the map?", k);
+ }
+ }
+
+ let mut m = HashMap::new();
+
+ let mut rng = {
+ let seed = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
+ SmallRng::from_seed(seed)
+ };
+
+ // Populate the map with some items.
+ for _ in 0..50 {
+ let x = rng.gen_range(-10, 10);
+ m.insert(x, ());
+ }
+
+ for _ in 0..1000 {
+ let x = rng.gen_range(-10, 10);
+ m.entry(x).and_replace_entry_with(|_, _| None);
+ check(&m);
+ }
+ }
+
+ #[test]
+ fn test_retain() {
+ let mut map: HashMap<i32, i32> = (0..100).map(|x| (x, x * 10)).collect();
+
+ map.retain(|&k, _| k % 2 == 0);
+ assert_eq!(map.len(), 50);
+ assert_eq!(map[&2], 20);
+ assert_eq!(map[&4], 40);
+ assert_eq!(map[&6], 60);
+ }
+
+ #[test]
+ fn test_drain_filter() {
+ {
+ let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect();
+ let drained = map.drain_filter(|&k, _| k % 2 == 0);
+ let mut out = drained.collect::<Vec<_>>();
+ out.sort_unstable();
+ assert_eq!(vec![(0, 0), (2, 20), (4, 40), (6, 60)], out);
+ assert_eq!(map.len(), 4);
+ }
+ {
+ let mut map: HashMap<i32, i32> = (0..8).map(|x| (x, x * 10)).collect();
+ drop(map.drain_filter(|&k, _| k % 2 == 0));
+ assert_eq!(map.len(), 4);
+ }
+ }
+
+ #[test]
+ #[cfg_attr(miri, ignore)] // FIXME: no OOM signalling (https://github.com/rust-lang/miri/issues/613)
+ fn test_try_reserve() {
+ let mut empty_bytes: HashMap<u8, u8> = HashMap::new();
+
+ const MAX_USIZE: usize = usize::MAX;
+
+ if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_USIZE) {
+ } else {
+ panic!("usize::MAX should trigger an overflow!");
+ }
+
+ if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_USIZE / 8) {
+ } else {
+ // This may succeed if there is enough free memory. Attempt to
+ // allocate a second hashmap to ensure the allocation will fail.
+ let mut empty_bytes2: HashMap<u8, u8> = HashMap::new();
+ if let Err(AllocError { .. }) = empty_bytes2.try_reserve(MAX_USIZE / 8) {
+ } else {
+ panic!("usize::MAX / 8 should trigger an OOM!");
+ }
+ }
+ }
+
+ #[test]
+ fn test_raw_entry() {
+ use super::RawEntryMut::{Occupied, Vacant};
+
+ let xs = [(1i32, 10i32), (2, 20), (3, 30), (4, 40), (5, 50), (6, 60)];
+
+ let mut map: HashMap<_, _> = xs.iter().cloned().collect();
+
+ let compute_hash = |map: &HashMap<i32, i32>, k: i32| -> u64 {
+ use core::hash::{BuildHasher, Hash, Hasher};
+
+ let mut hasher = map.hasher().build_hasher();
+ k.hash(&mut hasher);
+ hasher.finish()
+ };
+
+ // Existing key (insert)
+ match map.raw_entry_mut().from_key(&1) {
+ Vacant(_) => unreachable!(),
+ Occupied(mut view) => {
+ assert_eq!(view.get(), &10);
+ assert_eq!(view.insert(100), 10);
+ }
+ }
+ let hash1 = compute_hash(&map, 1);
+ assert_eq!(map.raw_entry().from_key(&1).unwrap(), (&1, &100));
+ assert_eq!(
+ map.raw_entry().from_hash(hash1, |k| *k == 1).unwrap(),
+ (&1, &100)
+ );
+ assert_eq!(
+ map.raw_entry().from_key_hashed_nocheck(hash1, &1).unwrap(),
+ (&1, &100)
+ );
+ assert_eq!(map.len(), 6);
+
+ // Existing key (update)
+ match map.raw_entry_mut().from_key(&2) {
+ Vacant(_) => unreachable!(),
+ Occupied(mut view) => {
+ let v = view.get_mut();
+ let new_v = (*v) * 10;
+ *v = new_v;
+ }
+ }
+ let hash2 = compute_hash(&map, 2);
+ assert_eq!(map.raw_entry().from_key(&2).unwrap(), (&2, &200));
+ assert_eq!(
+ map.raw_entry().from_hash(hash2, |k| *k == 2).unwrap(),
+ (&2, &200)
+ );
+ assert_eq!(
+ map.raw_entry().from_key_hashed_nocheck(hash2, &2).unwrap(),
+ (&2, &200)
+ );
+ assert_eq!(map.len(), 6);
+
+ // Existing key (take)
+ let hash3 = compute_hash(&map, 3);
+ match map.raw_entry_mut().from_key_hashed_nocheck(hash3, &3) {
+ Vacant(_) => unreachable!(),
+ Occupied(view) => {
+ assert_eq!(view.remove_entry(), (3, 30));
+ }
+ }
+ assert_eq!(map.raw_entry().from_key(&3), None);
+ assert_eq!(map.raw_entry().from_hash(hash3, |k| *k == 3), None);
+ assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash3, &3), None);
+ assert_eq!(map.len(), 5);
+
+ // Nonexistent key (insert)
+ match map.raw_entry_mut().from_key(&10) {
+ Occupied(_) => unreachable!(),
+ Vacant(view) => {
+ assert_eq!(view.insert(10, 1000), (&mut 10, &mut 1000));
+ }
+ }
+ assert_eq!(map.raw_entry().from_key(&10).unwrap(), (&10, &1000));
+ assert_eq!(map.len(), 6);
+
+ // Ensure all lookup methods produce equivalent results.
+ for k in 0..12 {
+ let hash = compute_hash(&map, k);
+ let v = map.get(&k).cloned();
+ let kv = v.as_ref().map(|v| (&k, v));
+
+ assert_eq!(map.raw_entry().from_key(&k), kv);
+ assert_eq!(map.raw_entry().from_hash(hash, |q| *q == k), kv);
+ assert_eq!(map.raw_entry().from_key_hashed_nocheck(hash, &k), kv);
+
+ match map.raw_entry_mut().from_key(&k) {
+ Occupied(mut o) => assert_eq!(Some(o.get_key_value()), kv),
+ Vacant(_) => assert_eq!(v, None),
+ }
+ match map.raw_entry_mut().from_key_hashed_nocheck(hash, &k) {
+ Occupied(mut o) => assert_eq!(Some(o.get_key_value()), kv),
+ Vacant(_) => assert_eq!(v, None),
+ }
+ match map.raw_entry_mut().from_hash(hash, |q| *q == k) {
+ Occupied(mut o) => assert_eq!(Some(o.get_key_value()), kv),
+ Vacant(_) => assert_eq!(v, None),
+ }
+ }
+ }
+
+ #[test]
+ fn test_key_without_hash_impl() {
+ #[derive(Debug)]
+ struct IntWrapper(u64);
+
+ let mut m: HashMap<IntWrapper, (), ()> = HashMap::default();
+ {
+ assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_none());
+ }
+ {
+ let vacant_entry = match m.raw_entry_mut().from_hash(0, |k| k.0 == 0) {
+ RawEntryMut::Occupied(..) => panic!("Found entry for key 0"),
+ RawEntryMut::Vacant(e) => e,
+ };
+ vacant_entry.insert_with_hasher(0, IntWrapper(0), (), |k| k.0);
+ }
+ {
+ assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_some());
+ assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_none());
+ assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none());
+ }
+ {
+ let vacant_entry = match m.raw_entry_mut().from_hash(1, |k| k.0 == 1) {
+ RawEntryMut::Occupied(..) => panic!("Found entry for key 1"),
+ RawEntryMut::Vacant(e) => e,
+ };
+ vacant_entry.insert_with_hasher(1, IntWrapper(1), (), |k| k.0);
+ }
+ {
+ assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_some());
+ assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_some());
+ assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none());
+ }
+ {
+ let occupied_entry = match m.raw_entry_mut().from_hash(0, |k| k.0 == 0) {
+ RawEntryMut::Occupied(e) => e,
+ RawEntryMut::Vacant(..) => panic!("Couldn't find entry for key 0"),
+ };
+ occupied_entry.remove();
+ }
+ assert!(m.raw_entry().from_hash(0, |k| k.0 == 0).is_none());
+ assert!(m.raw_entry().from_hash(1, |k| k.0 == 1).is_some());
+ assert!(m.raw_entry().from_hash(2, |k| k.0 == 2).is_none());
+ }
+
+ #[test]
+ #[cfg(feature = "raw")]
+ fn test_into_iter_refresh() {
+ use core::hash::{BuildHasher, Hash, Hasher};
+
+ #[cfg(miri)]
+ const N: usize = 32;
+ #[cfg(not(miri))]
+ const N: usize = 128;
+
+ let mut rng = rand::thread_rng();
+ for n in 0..N {
+ let mut m = HashMap::new();
+ for i in 0..n {
+ assert!(m.insert(i, 2 * i).is_none());
+ }
+ let hasher = m.hasher().clone();
+
+ let mut it = unsafe { m.table.iter() };
+ assert_eq!(it.len(), n);
+
+ let mut i = 0;
+ let mut left = n;
+ let mut removed = Vec::new();
+ loop {
+ // occasionally remove some elements
+ if i < n && rng.gen_bool(0.1) {
+ let mut hsh = hasher.build_hasher();
+ i.hash(&mut hsh);
+ let hash = hsh.finish();
+
+ unsafe {
+ let e = m.table.find(hash, |q| q.0.eq(&i));
+ if let Some(e) = e {
+ it.reflect_remove(&e);
+ let t = m.table.remove(e);
+ removed.push(t);
+ left -= 1;
+ } else {
+ assert!(removed.contains(&(i, 2 * i)), "{} not in {:?}", i, removed);
+ let e = m
+ .table
+ .insert(hash, (i, 2 * i), |x| super::make_hash(&hasher, &x.0));
+ it.reflect_insert(&e);
+ if let Some(p) = removed.iter().position(|e| e == &(i, 2 * i)) {
+ removed.swap_remove(p);
+ }
+ left += 1;
+ }
+ }
+ }
+
+ let e = it.next();
+ if e.is_none() {
+ break;
+ }
+ assert!(i < n);
+ let t = unsafe { e.unwrap().as_ref() };
+ assert!(!removed.contains(t));
+ let (k, v) = t;
+ assert_eq!(*v, 2 * k);
+ i += 1;
+ }
+ assert!(i <= n);
+
+ // just for safety:
+ assert_eq!(m.table.len(), left);
+ }
+ }
+
+ #[test]
+ fn test_const_with_hasher() {
+ use core::hash::BuildHasher;
+ use std::borrow::ToOwned;
+ use std::collections::hash_map::DefaultHasher;
+
+ #[derive(Clone)]
+ struct MyHasher;
+ impl BuildHasher for MyHasher {
+ type Hasher = DefaultHasher;
+
+ fn build_hasher(&self) -> DefaultHasher {
+ DefaultHasher::new()
+ }
+ }
+
+ const EMPTY_MAP: HashMap<u32, std::string::String, MyHasher> =
+ HashMap::with_hasher(MyHasher);
+
+ let mut map = EMPTY_MAP.clone();
+ map.insert(17, "seventeen".to_owned());
+ assert_eq!("seventeen", map[&17]);
+ }
+}
diff --git a/src/raw/bitmask.rs b/src/raw/bitmask.rs
new file mode 100644
index 0000000..99b2d53
--- /dev/null
+++ b/src/raw/bitmask.rs
@@ -0,0 +1,122 @@
+use super::imp::{BitMaskWord, BITMASK_MASK, BITMASK_STRIDE};
+#[cfg(feature = "nightly")]
+use core::intrinsics;
+
+/// A bit mask which contains the result of a `Match` operation on a `Group` and
+/// allows iterating through them.
+///
+/// The bit mask is arranged so that low-order bits represent lower memory
+/// addresses for group match results.
+///
+/// For implementation reasons, the bits in the set may be sparsely packed, so
+/// that there is only one bit-per-byte used (the high bit, 7). If this is the
+/// case, `BITMASK_STRIDE` will be 8 to indicate a divide-by-8 should be
+/// performed on counts/indices to normalize this difference. `BITMASK_MASK` is
+/// similarly a mask of all the actually-used bits.
+#[derive(Copy, Clone)]
+pub struct BitMask(pub BitMaskWord);
+
+#[allow(clippy::use_self)]
+impl BitMask {
+ /// Returns a new `BitMask` with all bits inverted.
+ #[inline]
+ #[must_use]
+ pub fn invert(self) -> Self {
+ BitMask(self.0 ^ BITMASK_MASK)
+ }
+
+ /// Flip the bit in the mask for the entry at the given index.
+ ///
+ /// Returns the bit's previous state.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)]
+ #[cfg(feature = "raw")]
+ pub unsafe fn flip(&mut self, index: usize) -> bool {
+ // NOTE: The + BITMASK_STRIDE - 1 is to set the high bit.
+ let mask = 1 << (index * BITMASK_STRIDE + BITMASK_STRIDE - 1);
+ self.0 ^= mask;
+ // The bit was set if the bit is now 0.
+ self.0 & mask == 0
+ }
+
+ /// Returns a new `BitMask` with the lowest bit removed.
+ #[inline]
+ #[must_use]
+ pub fn remove_lowest_bit(self) -> Self {
+ BitMask(self.0 & (self.0 - 1))
+ }
+ /// Returns whether the `BitMask` has at least one set bit.
+ #[inline]
+ pub fn any_bit_set(self) -> bool {
+ self.0 != 0
+ }
+
+ /// Returns the first set bit in the `BitMask`, if there is one.
+ #[inline]
+ pub fn lowest_set_bit(self) -> Option<usize> {
+ if self.0 == 0 {
+ None
+ } else {
+ Some(unsafe { self.lowest_set_bit_nonzero() })
+ }
+ }
+
+ /// Returns the first set bit in the `BitMask`, if there is one. The
+ /// bitmask must not be empty.
+ #[inline]
+ #[cfg(feature = "nightly")]
+ pub unsafe fn lowest_set_bit_nonzero(self) -> usize {
+ intrinsics::cttz_nonzero(self.0) as usize / BITMASK_STRIDE
+ }
+ #[inline]
+ #[cfg(not(feature = "nightly"))]
+ pub unsafe fn lowest_set_bit_nonzero(self) -> usize {
+ self.trailing_zeros()
+ }
+
+ /// Returns the number of trailing zeroes in the `BitMask`.
+ #[inline]
+ pub fn trailing_zeros(self) -> usize {
+ // ARM doesn't have a trailing_zeroes instruction, and instead uses
+ // reverse_bits (RBIT) + leading_zeroes (CLZ). However older ARM
+ // versions (pre-ARMv7) don't have RBIT and need to emulate it
+ // instead. Since we only have 1 bit set in each byte on ARM, we can
+ // use swap_bytes (REV) + leading_zeroes instead.
+ if cfg!(target_arch = "arm") && BITMASK_STRIDE % 8 == 0 {
+ self.0.swap_bytes().leading_zeros() as usize / BITMASK_STRIDE
+ } else {
+ self.0.trailing_zeros() as usize / BITMASK_STRIDE
+ }
+ }
+
+ /// Returns the number of leading zeroes in the `BitMask`.
+ #[inline]
+ pub fn leading_zeros(self) -> usize {
+ self.0.leading_zeros() as usize / BITMASK_STRIDE
+ }
+}
+
+impl IntoIterator for BitMask {
+ type Item = usize;
+ type IntoIter = BitMaskIter;
+
+ #[inline]
+ fn into_iter(self) -> BitMaskIter {
+ BitMaskIter(self)
+ }
+}
+
+/// Iterator over the contents of a `BitMask`, returning the indicies of set
+/// bits.
+pub struct BitMaskIter(BitMask);
+
+impl Iterator for BitMaskIter {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ let bit = self.0.lowest_set_bit()?;
+ self.0 = self.0.remove_lowest_bit();
+ Some(bit)
+ }
+}
diff --git a/src/raw/generic.rs b/src/raw/generic.rs
new file mode 100644
index 0000000..26f8c58
--- /dev/null
+++ b/src/raw/generic.rs
@@ -0,0 +1,151 @@
+use super::bitmask::BitMask;
+use super::EMPTY;
+use core::{mem, ptr};
+
+// Use the native word size as the group size. Using a 64-bit group size on
+// a 32-bit architecture will just end up being more expensive because
+// shifts and multiplies will need to be emulated.
+#[cfg(any(
+ target_pointer_width = "64",
+ target_arch = "aarch64",
+ target_arch = "x86_64",
+))]
+type GroupWord = u64;
+#[cfg(all(
+ target_pointer_width = "32",
+ not(target_arch = "aarch64"),
+ not(target_arch = "x86_64"),
+))]
+type GroupWord = u32;
+
+pub type BitMaskWord = GroupWord;
+pub const BITMASK_STRIDE: usize = 8;
+// We only care about the highest bit of each byte for the mask.
+#[allow(clippy::cast_possible_truncation, clippy::unnecessary_cast)]
+pub const BITMASK_MASK: BitMaskWord = 0x8080_8080_8080_8080_u64 as GroupWord;
+
+/// Helper function to replicate a byte across a `GroupWord`.
+#[inline]
+fn repeat(byte: u8) -> GroupWord {
+ GroupWord::from_ne_bytes([byte; Group::WIDTH])
+}
+
+/// Abstraction over a group of control bytes which can be scanned in
+/// parallel.
+///
+/// This implementation uses a word-sized integer.
+#[derive(Copy, Clone)]
+pub struct Group(GroupWord);
+
+// We perform all operations in the native endianess, and convert to
+// little-endian just before creating a BitMask. The can potentially
+// enable the compiler to eliminate unnecessary byte swaps if we are
+// only checking whether a BitMask is empty.
+#[allow(clippy::use_self)]
+impl Group {
+ /// Number of bytes in the group.
+ pub const WIDTH: usize = mem::size_of::<Self>();
+
+ /// Returns a full group of empty bytes, suitable for use as the initial
+ /// value for an empty hash table.
+ ///
+ /// This is guaranteed to be aligned to the group size.
+ pub const fn static_empty() -> &'static [u8; Group::WIDTH] {
+ #[repr(C)]
+ struct AlignedBytes {
+ _align: [Group; 0],
+ bytes: [u8; Group::WIDTH],
+ };
+ const ALIGNED_BYTES: AlignedBytes = AlignedBytes {
+ _align: [],
+ bytes: [EMPTY; Group::WIDTH],
+ };
+ &ALIGNED_BYTES.bytes
+ }
+
+ /// Loads a group of bytes starting at the given address.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)] // unaligned load
+ pub unsafe fn load(ptr: *const u8) -> Self {
+ Group(ptr::read_unaligned(ptr as *const _))
+ }
+
+ /// Loads a group of bytes starting at the given address, which must be
+ /// aligned to `mem::align_of::<Group>()`.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)]
+ pub unsafe fn load_aligned(ptr: *const u8) -> Self {
+ // FIXME: use align_offset once it stabilizes
+ debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0);
+ Group(ptr::read(ptr as *const _))
+ }
+
+ /// Stores the group of bytes to the given address, which must be
+ /// aligned to `mem::align_of::<Group>()`.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)]
+ pub unsafe fn store_aligned(self, ptr: *mut u8) {
+ // FIXME: use align_offset once it stabilizes
+ debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0);
+ ptr::write(ptr as *mut _, self.0);
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which *may*
+ /// have the given value.
+ ///
+ /// This function may return a false positive in certain cases where
+ /// the byte in the group differs from the searched value only in its
+ /// lowest bit. This is fine because:
+ /// - This never happens for `EMPTY` and `DELETED`, only full entries.
+ /// - The check for key equality will catch these.
+ /// - This only happens if there is at least 1 true match.
+ /// - The chance of this happening is very low (< 1% chance per byte).
+ #[inline]
+ pub fn match_byte(self, byte: u8) -> BitMask {
+ // This algorithm is derived from
+ // http://graphics.stanford.edu/~seander/bithacks.html##ValueInWord
+ let cmp = self.0 ^ repeat(byte);
+ BitMask((cmp.wrapping_sub(repeat(0x01)) & !cmp & repeat(0x80)).to_le())
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which are
+ /// `EMPTY`.
+ #[inline]
+ pub fn match_empty(self) -> BitMask {
+ // If the high bit is set, then the byte must be either:
+ // 1111_1111 (EMPTY) or 1000_0000 (DELETED).
+ // So we can just check if the top two bits are 1 by ANDing them.
+ BitMask((self.0 & (self.0 << 1) & repeat(0x80)).to_le())
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which are
+ /// `EMPTY` or `DELETED`.
+ #[inline]
+ pub fn match_empty_or_deleted(self) -> BitMask {
+ // A byte is EMPTY or DELETED iff the high bit is set
+ BitMask((self.0 & repeat(0x80)).to_le())
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which are full.
+ #[inline]
+ pub fn match_full(self) -> BitMask {
+ self.match_empty_or_deleted().invert()
+ }
+
+ /// Performs the following transformation on all bytes in the group:
+ /// - `EMPTY => EMPTY`
+ /// - `DELETED => EMPTY`
+ /// - `FULL => DELETED`
+ #[inline]
+ pub fn convert_special_to_empty_and_full_to_deleted(self) -> Self {
+ // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111
+ // and high_bit = 0 (FULL) to 1000_0000
+ //
+ // Here's this logic expanded to concrete values:
+ // let full = 1000_0000 (true) or 0000_0000 (false)
+ // !1000_0000 + 1 = 0111_1111 + 1 = 1000_0000 (no carry)
+ // !0000_0000 + 0 = 1111_1111 + 0 = 1111_1111 (no carry)
+ let full = !self.0 & repeat(0x80);
+ Group(!full + (full >> 7))
+ }
+}
diff --git a/src/raw/mod.rs b/src/raw/mod.rs
new file mode 100644
index 0000000..32fec98
--- /dev/null
+++ b/src/raw/mod.rs
@@ -0,0 +1,1924 @@
+use crate::alloc::alloc::{alloc, dealloc, handle_alloc_error};
+use crate::scopeguard::guard;
+use crate::TryReserveError;
+use core::alloc::Layout;
+use core::hint;
+use core::iter::FusedIterator;
+use core::marker::PhantomData;
+use core::mem;
+use core::mem::ManuallyDrop;
+use core::ptr::NonNull;
+
+cfg_if! {
+ // Use the SSE2 implementation if possible: it allows us to scan 16 buckets
+ // at once instead of 8. We don't bother with AVX since it would require
+ // runtime dispatch and wouldn't gain us much anyways: the probability of
+ // finding a match drops off drastically after the first few buckets.
+ //
+ // I attempted an implementation on ARM using NEON instructions, but it
+ // turns out that most NEON instructions have multi-cycle latency, which in
+ // the end outweighs any gains over the generic implementation.
+ if #[cfg(all(
+ target_feature = "sse2",
+ any(target_arch = "x86", target_arch = "x86_64"),
+ not(miri)
+ ))] {
+ mod sse2;
+ use sse2 as imp;
+ } else {
+ #[path = "generic.rs"]
+ mod generic;
+ use generic as imp;
+ }
+}
+
+mod bitmask;
+
+use self::bitmask::{BitMask, BitMaskIter};
+use self::imp::Group;
+
+// Branch prediction hint. This is currently only available on nightly but it
+// consistently improves performance by 10-15%.
+#[cfg(feature = "nightly")]
+use core::intrinsics::{likely, unlikely};
+#[cfg(not(feature = "nightly"))]
+#[inline]
+fn likely(b: bool) -> bool {
+ b
+}
+#[cfg(not(feature = "nightly"))]
+#[inline]
+fn unlikely(b: bool) -> bool {
+ b
+}
+
+#[cfg(feature = "nightly")]
+#[cfg_attr(feature = "inline-more", inline)]
+unsafe fn offset_from<T>(to: *const T, from: *const T) -> usize {
+ to.offset_from(from) as usize
+}
+#[cfg(not(feature = "nightly"))]
+#[cfg_attr(feature = "inline-more", inline)]
+unsafe fn offset_from<T>(to: *const T, from: *const T) -> usize {
+ (to as usize - from as usize) / mem::size_of::<T>()
+}
+
+/// Whether memory allocation errors should return an error or abort.
+#[derive(Copy, Clone)]
+enum Fallibility {
+ Fallible,
+ Infallible,
+}
+
+impl Fallibility {
+ /// Error to return on capacity overflow.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn capacity_overflow(self) -> TryReserveError {
+ match self {
+ Fallibility::Fallible => TryReserveError::CapacityOverflow,
+ Fallibility::Infallible => panic!("Hash table capacity overflow"),
+ }
+ }
+
+ /// Error to return on allocation error.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn alloc_err(self, layout: Layout) -> TryReserveError {
+ match self {
+ Fallibility::Fallible => TryReserveError::AllocError { layout },
+ Fallibility::Infallible => handle_alloc_error(layout),
+ }
+ }
+}
+
+/// Control byte value for an empty bucket.
+const EMPTY: u8 = 0b1111_1111;
+
+/// Control byte value for a deleted bucket.
+const DELETED: u8 = 0b1000_0000;
+
+/// Checks whether a control byte represents a full bucket (top bit is clear).
+#[inline]
+fn is_full(ctrl: u8) -> bool {
+ ctrl & 0x80 == 0
+}
+
+/// Checks whether a control byte represents a special value (top bit is set).
+#[inline]
+fn is_special(ctrl: u8) -> bool {
+ ctrl & 0x80 != 0
+}
+
+/// Checks whether a special control value is EMPTY (just check 1 bit).
+#[inline]
+fn special_is_empty(ctrl: u8) -> bool {
+ debug_assert!(is_special(ctrl));
+ ctrl & 0x01 != 0
+}
+
+/// Primary hash function, used to select the initial bucket to probe from.
+#[inline]
+#[allow(clippy::cast_possible_truncation)]
+fn h1(hash: u64) -> usize {
+ // On 32-bit platforms we simply ignore the higher hash bits.
+ hash as usize
+}
+
+/// Secondary hash function, saved in the low 7 bits of the control byte.
+#[inline]
+#[allow(clippy::cast_possible_truncation)]
+fn h2(hash: u64) -> u8 {
+ // Grab the top 7 bits of the hash. While the hash is normally a full 64-bit
+ // value, some hash functions (such as FxHash) produce a usize result
+ // instead, which means that the top 32 bits are 0 on 32-bit platforms.
+ let hash_len = usize::min(mem::size_of::<usize>(), mem::size_of::<u64>());
+ let top7 = hash >> (hash_len * 8 - 7);
+ (top7 & 0x7f) as u8 // truncation
+}
+
+/// Probe sequence based on triangular numbers, which is guaranteed (since our
+/// table size is a power of two) to visit every group of elements exactly once.
+///
+/// A triangular probe has us jump by 1 more group every time. So first we
+/// jump by 1 group (meaning we just continue our linear scan), then 2 groups
+/// (skipping over 1 group), then 3 groups (skipping over 2 groups), and so on.
+///
+/// Proof that the probe will visit every group in the table:
+/// <https://fgiesen.wordpress.com/2015/02/22/triangular-numbers-mod-2n/>
+struct ProbeSeq {
+ bucket_mask: usize,
+ pos: usize,
+ stride: usize,
+}
+
+impl Iterator for ProbeSeq {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ // We should have found an empty bucket by now and ended the probe.
+ debug_assert!(
+ self.stride <= self.bucket_mask,
+ "Went past end of probe sequence"
+ );
+
+ let result = self.pos;
+ self.stride += Group::WIDTH;
+ self.pos += self.stride;
+ self.pos &= self.bucket_mask;
+ Some(result)
+ }
+}
+
+/// Returns the number of buckets needed to hold the given number of items,
+/// taking the maximum load factor into account.
+///
+/// Returns `None` if an overflow occurs.
+// Workaround for emscripten bug emscripten-core/emscripten-fastcomp#258
+#[cfg_attr(target_os = "emscripten", inline(never))]
+#[cfg_attr(not(target_os = "emscripten"), inline)]
+fn capacity_to_buckets(cap: usize) -> Option<usize> {
+ debug_assert_ne!(cap, 0);
+
+ // For small tables we require at least 1 empty bucket so that lookups are
+ // guaranteed to terminate if an element doesn't exist in the table.
+ if cap < 8 {
+ // We don't bother with a table size of 2 buckets since that can only
+ // hold a single element. Instead we skip directly to a 4 bucket table
+ // which can hold 3 elements.
+ return Some(if cap < 4 { 4 } else { 8 });
+ }
+
+ // Otherwise require 1/8 buckets to be empty (87.5% load)
+ //
+ // Be careful when modifying this, calculate_layout relies on the
+ // overflow check here.
+ let adjusted_cap = cap.checked_mul(8)? / 7;
+
+ // Any overflows will have been caught by the checked_mul. Also, any
+ // rounding errors from the division above will be cleaned up by
+ // next_power_of_two (which can't overflow because of the previous divison).
+ Some(adjusted_cap.next_power_of_two())
+}
+
+/// Returns the maximum effective capacity for the given bucket mask, taking
+/// the maximum load factor into account.
+#[inline]
+fn bucket_mask_to_capacity(bucket_mask: usize) -> usize {
+ if bucket_mask < 8 {
+ // For tables with 1/2/4/8 buckets, we always reserve one empty slot.
+ // Keep in mind that the bucket mask is one less than the bucket count.
+ bucket_mask
+ } else {
+ // For larger tables we reserve 12.5% of the slots as empty.
+ ((bucket_mask + 1) / 8) * 7
+ }
+}
+
+/// Returns a Layout which describes the allocation required for a hash table,
+/// and the offset of the control bytes in the allocation.
+/// (the offset is also one past last element of buckets)
+///
+/// Returns `None` if an overflow occurs.
+#[cfg_attr(feature = "inline-more", inline)]
+#[cfg(feature = "nightly")]
+fn calculate_layout<T>(buckets: usize) -> Option<(Layout, usize)> {
+ debug_assert!(buckets.is_power_of_two());
+
+ // Array of buckets
+ let data = Layout::array::<T>(buckets).ok()?;
+
+ // Array of control bytes. This must be aligned to the group size.
+ //
+ // We add `Group::WIDTH` control bytes at the end of the array which
+ // replicate the bytes at the start of the array and thus avoids the need to
+ // perform bounds-checking while probing.
+ //
+ // There is no possible overflow here since buckets is a power of two and
+ // Group::WIDTH is a small number.
+ let ctrl = unsafe { Layout::from_size_align_unchecked(buckets + Group::WIDTH, Group::WIDTH) };
+
+ data.extend(ctrl).ok()
+}
+
+/// Returns a Layout which describes the allocation required for a hash table,
+/// and the offset of the control bytes in the allocation.
+/// (the offset is also one past last element of buckets)
+///
+/// Returns `None` if an overflow occurs.
+#[cfg_attr(feature = "inline-more", inline)]
+#[cfg(not(feature = "nightly"))]
+fn calculate_layout<T>(buckets: usize) -> Option<(Layout, usize)> {
+ debug_assert!(buckets.is_power_of_two());
+
+ // Manual layout calculation since Layout methods are not yet stable.
+ let ctrl_align = usize::max(mem::align_of::<T>(), Group::WIDTH);
+ let ctrl_offset = mem::size_of::<T>()
+ .checked_mul(buckets)?
+ .checked_add(ctrl_align - 1)?
+ & !(ctrl_align - 1);
+ let len = ctrl_offset.checked_add(buckets + Group::WIDTH)?;
+
+ Some((
+ unsafe { Layout::from_size_align_unchecked(len, ctrl_align) },
+ ctrl_offset,
+ ))
+}
+
+/// A reference to a hash table bucket containing a `T`.
+///
+/// This is usually just a pointer to the element itself. However if the element
+/// is a ZST, then we instead track the index of the element in the table so
+/// that `erase` works properly.
+pub struct Bucket<T> {
+ // Actually it is pointer to next element than element itself
+ // this is needed to maintain pointer arithmetic invariants
+ // keeping direct pointer to element introduces difficulty.
+ // Using `NonNull` for variance and niche layout
+ ptr: NonNull<T>,
+}
+
+// This Send impl is needed for rayon support. This is safe since Bucket is
+// never exposed in a public API.
+unsafe impl<T> Send for Bucket<T> {}
+
+impl<T> Clone for Bucket<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Self { ptr: self.ptr }
+ }
+}
+
+impl<T> Bucket<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn from_base_index(base: NonNull<T>, index: usize) -> Self {
+ let ptr = if mem::size_of::<T>() == 0 {
+ // won't overflow because index must be less than length
+ (index + 1) as *mut T
+ } else {
+ base.as_ptr().sub(index)
+ };
+ Self {
+ ptr: NonNull::new_unchecked(ptr),
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn to_base_index(&self, base: NonNull<T>) -> usize {
+ if mem::size_of::<T>() == 0 {
+ self.ptr.as_ptr() as usize - 1
+ } else {
+ offset_from(base.as_ptr(), self.ptr.as_ptr())
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn as_ptr(&self) -> *mut T {
+ if mem::size_of::<T>() == 0 {
+ // Just return an arbitrary ZST pointer which is properly aligned
+ mem::align_of::<T>() as *mut T
+ } else {
+ self.ptr.as_ptr().sub(1)
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn next_n(&self, offset: usize) -> Self {
+ let ptr = if mem::size_of::<T>() == 0 {
+ (self.ptr.as_ptr() as usize + offset) as *mut T
+ } else {
+ self.ptr.as_ptr().sub(offset)
+ };
+ Self {
+ ptr: NonNull::new_unchecked(ptr),
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn drop(&self) {
+ self.as_ptr().drop_in_place();
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn read(&self) -> T {
+ self.as_ptr().read()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn write(&self, val: T) {
+ self.as_ptr().write(val);
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn as_ref<'a>(&self) -> &'a T {
+ &*self.as_ptr()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn as_mut<'a>(&self) -> &'a mut T {
+ &mut *self.as_ptr()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn copy_from_nonoverlapping(&self, other: &Self) {
+ self.as_ptr().copy_from_nonoverlapping(other.as_ptr(), 1);
+ }
+}
+
+/// A raw hash table with an unsafe API.
+pub struct RawTable<T> {
+ // Mask to get an index from a hash value. The value is one less than the
+ // number of buckets in the table.
+ bucket_mask: usize,
+
+ // [Padding], T1, T2, ..., Tlast, C1, C2, ...
+ // ^ points here
+ ctrl: NonNull<u8>,
+
+ // Number of elements that can be inserted before we need to grow the table
+ growth_left: usize,
+
+ // Number of elements in the table, only really used by len()
+ items: usize,
+
+ // Tell dropck that we own instances of T.
+ marker: PhantomData<T>,
+}
+
+impl<T> RawTable<T> {
+ /// Creates a new empty hash table without allocating any memory.
+ ///
+ /// In effect this returns a table with exactly 1 bucket. However we can
+ /// leave the data pointer dangling since that bucket is never written to
+ /// due to our load factor forcing us to always have at least 1 free bucket.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub const fn new() -> Self {
+ Self {
+ // Be careful to cast the entire slice to a raw pointer.
+ ctrl: unsafe { NonNull::new_unchecked(Group::static_empty() as *const _ as *mut u8) },
+ bucket_mask: 0,
+ items: 0,
+ growth_left: 0,
+ marker: PhantomData,
+ }
+ }
+
+ /// Allocates a new hash table with the given number of buckets.
+ ///
+ /// The control bytes are left uninitialized.
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn new_uninitialized(
+ buckets: usize,
+ fallability: Fallibility,
+ ) -> Result<Self, TryReserveError> {
+ debug_assert!(buckets.is_power_of_two());
+
+ // Avoid `Option::ok_or_else` because it bloats LLVM IR.
+ let (layout, ctrl_offset) = match calculate_layout::<T>(buckets) {
+ Some(lco) => lco,
+ None => return Err(fallability.capacity_overflow()),
+ };
+ let ptr = match NonNull::new(alloc(layout)) {
+ Some(ptr) => ptr,
+ None => return Err(fallability.alloc_err(layout)),
+ };
+ let ctrl = NonNull::new_unchecked(ptr.as_ptr().add(ctrl_offset));
+ Ok(Self {
+ ctrl,
+ bucket_mask: buckets - 1,
+ items: 0,
+ growth_left: bucket_mask_to_capacity(buckets - 1),
+ marker: PhantomData,
+ })
+ }
+
+ /// Attempts to allocate a new hash table with at least enough capacity
+ /// for inserting the given number of elements without reallocating.
+ fn fallible_with_capacity(
+ capacity: usize,
+ fallability: Fallibility,
+ ) -> Result<Self, TryReserveError> {
+ if capacity == 0 {
+ Ok(Self::new())
+ } else {
+ unsafe {
+ // Avoid `Option::ok_or_else` because it bloats LLVM IR.
+ let buckets = match capacity_to_buckets(capacity) {
+ Some(buckets) => buckets,
+ None => return Err(fallability.capacity_overflow()),
+ };
+ let result = Self::new_uninitialized(buckets, fallability)?;
+ result.ctrl(0).write_bytes(EMPTY, result.num_ctrl_bytes());
+
+ Ok(result)
+ }
+ }
+ }
+
+ /// Attempts to allocate a new hash table with at least enough capacity
+ /// for inserting the given number of elements without reallocating.
+ #[cfg(feature = "raw")]
+ pub fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> {
+ Self::fallible_with_capacity(capacity, Fallibility::Fallible)
+ }
+
+ /// Allocates a new hash table with at least enough capacity for inserting
+ /// the given number of elements without reallocating.
+ pub fn with_capacity(capacity: usize) -> Self {
+ // Avoid `Result::unwrap_or_else` because it bloats LLVM IR.
+ match Self::fallible_with_capacity(capacity, Fallibility::Infallible) {
+ Ok(capacity) => capacity,
+ Err(_) => unsafe { hint::unreachable_unchecked() },
+ }
+ }
+
+ /// Deallocates the table without dropping any entries.
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn free_buckets(&mut self) {
+ // Avoid `Option::unwrap_or_else` because it bloats LLVM IR.
+ let (layout, ctrl_offset) = match calculate_layout::<T>(self.buckets()) {
+ Some(lco) => lco,
+ None => hint::unreachable_unchecked(),
+ };
+ dealloc(self.ctrl.as_ptr().sub(ctrl_offset), layout);
+ }
+
+ /// Returns pointer to one past last element of data table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn data_end(&self) -> NonNull<T> {
+ NonNull::new_unchecked(self.ctrl.as_ptr() as *mut T)
+ }
+
+ /// Returns pointer to start of data table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[cfg(feature = "nightly")]
+ pub unsafe fn data_start(&self) -> *mut T {
+ self.data_end().as_ptr().wrapping_sub(self.buckets())
+ }
+
+ /// Returns the index of a bucket from a `Bucket`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn bucket_index(&self, bucket: &Bucket<T>) -> usize {
+ bucket.to_base_index(self.data_end())
+ }
+
+ /// Returns a pointer to a control byte.
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn ctrl(&self, index: usize) -> *mut u8 {
+ debug_assert!(index < self.num_ctrl_bytes());
+ self.ctrl.as_ptr().add(index)
+ }
+
+ /// Returns a pointer to an element in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn bucket(&self, index: usize) -> Bucket<T> {
+ debug_assert_ne!(self.bucket_mask, 0);
+ debug_assert!(index < self.buckets());
+ Bucket::from_base_index(self.data_end(), index)
+ }
+
+ /// Erases an element from the table without dropping it.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[deprecated(since = "0.8.1", note = "use erase or remove instead")]
+ pub unsafe fn erase_no_drop(&mut self, item: &Bucket<T>) {
+ let index = self.bucket_index(item);
+ debug_assert!(is_full(*self.ctrl(index)));
+ let index_before = index.wrapping_sub(Group::WIDTH) & self.bucket_mask;
+ let empty_before = Group::load(self.ctrl(index_before)).match_empty();
+ let empty_after = Group::load(self.ctrl(index)).match_empty();
+
+ // If we are inside a continuous block of Group::WIDTH full or deleted
+ // cells then a probe window may have seen a full block when trying to
+ // insert. We therefore need to keep that block non-empty so that
+ // lookups will continue searching to the next probe window.
+ //
+ // Note that in this context `leading_zeros` refers to the bytes at the
+ // end of a group, while `trailing_zeros` refers to the bytes at the
+ // begining of a group.
+ let ctrl = if empty_before.leading_zeros() + empty_after.trailing_zeros() >= Group::WIDTH {
+ DELETED
+ } else {
+ self.growth_left += 1;
+ EMPTY
+ };
+ self.set_ctrl(index, ctrl);
+ self.items -= 1;
+ }
+
+ /// Erases an element from the table, dropping it in place.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::needless_pass_by_value)]
+ #[allow(deprecated)]
+ pub unsafe fn erase(&mut self, item: Bucket<T>) {
+ // Erase the element from the table first since drop might panic.
+ self.erase_no_drop(&item);
+ item.drop();
+ }
+
+ /// Finds and erases an element from the table, dropping it in place.
+ /// Returns true if an element was found.
+ #[cfg(feature = "raw")]
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn erase_entry(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> bool {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ if let Some(bucket) = self.find(hash, eq) {
+ unsafe { self.erase(bucket) };
+ true
+ } else {
+ false
+ }
+ }
+
+ /// Removes an element from the table, returning it.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[allow(clippy::needless_pass_by_value)]
+ #[allow(deprecated)]
+ pub unsafe fn remove(&mut self, item: Bucket<T>) -> T {
+ self.erase_no_drop(&item);
+ item.read()
+ }
+
+ /// Finds and removes an element from the table, returning it.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove_entry(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<T> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.find(hash, eq) {
+ Some(bucket) => Some(unsafe { self.remove(bucket) }),
+ None => None,
+ }
+ }
+
+ /// Returns an iterator for a probe sequence on the table.
+ ///
+ /// This iterator never terminates, but is guaranteed to visit each bucket
+ /// group exactly once. The loop using `probe_seq` must terminate upon
+ /// reaching a group containing an empty bucket.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn probe_seq(&self, hash: u64) -> ProbeSeq {
+ ProbeSeq {
+ bucket_mask: self.bucket_mask,
+ pos: h1(hash) & self.bucket_mask,
+ stride: 0,
+ }
+ }
+
+ /// Sets a control byte, and possibly also the replicated control byte at
+ /// the end of the array.
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn set_ctrl(&self, index: usize, ctrl: u8) {
+ // Replicate the first Group::WIDTH control bytes at the end of
+ // the array without using a branch:
+ // - If index >= Group::WIDTH then index == index2.
+ // - Otherwise index2 == self.bucket_mask + 1 + index.
+ //
+ // The very last replicated control byte is never actually read because
+ // we mask the initial index for unaligned loads, but we write it
+ // anyways because it makes the set_ctrl implementation simpler.
+ //
+ // If there are fewer buckets than Group::WIDTH then this code will
+ // replicate the buckets at the end of the trailing group. For example
+ // with 2 buckets and a group size of 4, the control bytes will look
+ // like this:
+ //
+ // Real | Replicated
+ // ---------------------------------------------
+ // | [A] | [B] | [EMPTY] | [EMPTY] | [A] | [B] |
+ // ---------------------------------------------
+ let index2 = ((index.wrapping_sub(Group::WIDTH)) & self.bucket_mask) + Group::WIDTH;
+
+ *self.ctrl(index) = ctrl;
+ *self.ctrl(index2) = ctrl;
+ }
+
+ /// Searches for an empty or deleted bucket which is suitable for inserting
+ /// a new element.
+ ///
+ /// There must be at least 1 empty bucket in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn find_insert_slot(&self, hash: u64) -> usize {
+ for pos in self.probe_seq(hash) {
+ unsafe {
+ let group = Group::load(self.ctrl(pos));
+ if let Some(bit) = group.match_empty_or_deleted().lowest_set_bit() {
+ let result = (pos + bit) & self.bucket_mask;
+
+ // In tables smaller than the group width, trailing control
+ // bytes outside the range of the table are filled with
+ // EMPTY entries. These will unfortunately trigger a
+ // match, but once masked may point to a full bucket that
+ // is already occupied. We detect this situation here and
+ // perform a second scan starting at the begining of the
+ // table. This second scan is guaranteed to find an empty
+ // slot (due to the load factor) before hitting the trailing
+ // control bytes (containing EMPTY).
+ if unlikely(is_full(*self.ctrl(result))) {
+ debug_assert!(self.bucket_mask < Group::WIDTH);
+ debug_assert_ne!(pos, 0);
+ return Group::load_aligned(self.ctrl(0))
+ .match_empty_or_deleted()
+ .lowest_set_bit_nonzero();
+ } else {
+ return result;
+ }
+ }
+ }
+ }
+
+ // probe_seq never returns.
+ unreachable!();
+ }
+
+ /// Marks all table buckets as empty without dropping their contents.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn clear_no_drop(&mut self) {
+ if !self.is_empty_singleton() {
+ unsafe {
+ self.ctrl(0).write_bytes(EMPTY, self.num_ctrl_bytes());
+ }
+ }
+ self.items = 0;
+ self.growth_left = bucket_mask_to_capacity(self.bucket_mask);
+ }
+
+ /// Removes all elements from the table without freeing the backing memory.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn clear(&mut self) {
+ // Ensure that the table is reset even if one of the drops panic
+ let self_ = guard(self, |self_| self_.clear_no_drop());
+
+ if mem::needs_drop::<T>() && self_.len() != 0 {
+ unsafe {
+ for item in self_.iter() {
+ item.drop();
+ }
+ }
+ }
+ }
+
+ /// Shrinks the table to fit `max(self.len(), min_size)` elements.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn shrink_to(&mut self, min_size: usize, hasher: impl Fn(&T) -> u64) {
+ // Calculate the minimal number of elements that we need to reserve
+ // space for.
+ let min_size = usize::max(self.items, min_size);
+ if min_size == 0 {
+ *self = Self::new();
+ return;
+ }
+
+ // Calculate the number of buckets that we need for this number of
+ // elements. If the calculation overflows then the requested bucket
+ // count must be larger than what we have right and nothing needs to be
+ // done.
+ let min_buckets = match capacity_to_buckets(min_size) {
+ Some(buckets) => buckets,
+ None => return,
+ };
+
+ // If we have more buckets than we need, shrink the table.
+ if min_buckets < self.buckets() {
+ // Fast path if the table is empty
+ if self.items == 0 {
+ *self = Self::with_capacity(min_size)
+ } else {
+ // Avoid `Result::unwrap_or_else` because it bloats LLVM IR.
+ if self
+ .resize(min_size, hasher, Fallibility::Infallible)
+ .is_err()
+ {
+ unsafe { hint::unreachable_unchecked() }
+ }
+ }
+ }
+ }
+
+ /// Ensures that at least `additional` items can be inserted into the table
+ /// without reallocation.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn reserve(&mut self, additional: usize, hasher: impl Fn(&T) -> u64) {
+ if additional > self.growth_left {
+ // Avoid `Result::unwrap_or_else` because it bloats LLVM IR.
+ if self
+ .reserve_rehash(additional, hasher, Fallibility::Infallible)
+ .is_err()
+ {
+ unsafe { hint::unreachable_unchecked() }
+ }
+ }
+ }
+
+ /// Tries to ensure that at least `additional` items can be inserted into
+ /// the table without reallocation.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn try_reserve(
+ &mut self,
+ additional: usize,
+ hasher: impl Fn(&T) -> u64,
+ ) -> Result<(), TryReserveError> {
+ if additional > self.growth_left {
+ self.reserve_rehash(additional, hasher, Fallibility::Fallible)
+ } else {
+ Ok(())
+ }
+ }
+
+ /// Out-of-line slow path for `reserve` and `try_reserve`.
+ #[cold]
+ #[inline(never)]
+ fn reserve_rehash(
+ &mut self,
+ additional: usize,
+ hasher: impl Fn(&T) -> u64,
+ fallability: Fallibility,
+ ) -> Result<(), TryReserveError> {
+ // Avoid `Option::ok_or_else` because it bloats LLVM IR.
+ let new_items = match self.items.checked_add(additional) {
+ Some(new_items) => new_items,
+ None => return Err(fallability.capacity_overflow()),
+ };
+ let full_capacity = bucket_mask_to_capacity(self.bucket_mask);
+ if new_items <= full_capacity / 2 {
+ // Rehash in-place without re-allocating if we have plenty of spare
+ // capacity that is locked up due to DELETED entries.
+ self.rehash_in_place(hasher);
+ Ok(())
+ } else {
+ // Otherwise, conservatively resize to at least the next size up
+ // to avoid churning deletes into frequent rehashes.
+ self.resize(
+ usize::max(new_items, full_capacity + 1),
+ hasher,
+ fallability,
+ )
+ }
+ }
+
+ /// Rehashes the contents of the table in place (i.e. without changing the
+ /// allocation).
+ ///
+ /// If `hasher` panics then some the table's contents may be lost.
+ fn rehash_in_place(&mut self, hasher: impl Fn(&T) -> u64) {
+ unsafe {
+ // Bulk convert all full control bytes to DELETED, and all DELETED
+ // control bytes to EMPTY. This effectively frees up all buckets
+ // containing a DELETED entry.
+ for i in (0..self.buckets()).step_by(Group::WIDTH) {
+ let group = Group::load_aligned(self.ctrl(i));
+ let group = group.convert_special_to_empty_and_full_to_deleted();
+ group.store_aligned(self.ctrl(i));
+ }
+
+ // Fix up the trailing control bytes. See the comments in set_ctrl
+ // for the handling of tables smaller than the group width.
+ if self.buckets() < Group::WIDTH {
+ self.ctrl(0)
+ .copy_to(self.ctrl(Group::WIDTH), self.buckets());
+ } else {
+ self.ctrl(0)
+ .copy_to(self.ctrl(self.buckets()), Group::WIDTH);
+ }
+
+ // If the hash function panics then properly clean up any elements
+ // that we haven't rehashed yet. We unfortunately can't preserve the
+ // element since we lost their hash and have no way of recovering it
+ // without risking another panic.
+ let mut guard = guard(self, |self_| {
+ if mem::needs_drop::<T>() {
+ for i in 0..self_.buckets() {
+ if *self_.ctrl(i) == DELETED {
+ self_.set_ctrl(i, EMPTY);
+ self_.bucket(i).drop();
+ self_.items -= 1;
+ }
+ }
+ }
+ self_.growth_left = bucket_mask_to_capacity(self_.bucket_mask) - self_.items;
+ });
+
+ // At this point, DELETED elements are elements that we haven't
+ // rehashed yet. Find them and re-insert them at their ideal
+ // position.
+ 'outer: for i in 0..guard.buckets() {
+ if *guard.ctrl(i) != DELETED {
+ continue;
+ }
+ 'inner: loop {
+ // Hash the current item
+ let item = guard.bucket(i);
+ let hash = hasher(item.as_ref());
+
+ // Search for a suitable place to put it
+ let new_i = guard.find_insert_slot(hash);
+
+ // Probing works by scanning through all of the control
+ // bytes in groups, which may not be aligned to the group
+ // size. If both the new and old position fall within the
+ // same unaligned group, then there is no benefit in moving
+ // it and we can just continue to the next item.
+ let probe_index = |pos: usize| {
+ (pos.wrapping_sub(guard.probe_seq(hash).pos) & guard.bucket_mask)
+ / Group::WIDTH
+ };
+ if likely(probe_index(i) == probe_index(new_i)) {
+ guard.set_ctrl(i, h2(hash));
+ continue 'outer;
+ }
+
+ // We are moving the current item to a new position. Write
+ // our H2 to the control byte of the new position.
+ let prev_ctrl = *guard.ctrl(new_i);
+ guard.set_ctrl(new_i, h2(hash));
+
+ if prev_ctrl == EMPTY {
+ // If the target slot is empty, simply move the current
+ // element into the new slot and clear the old control
+ // byte.
+ guard.set_ctrl(i, EMPTY);
+ guard.bucket(new_i).copy_from_nonoverlapping(&item);
+ continue 'outer;
+ } else {
+ // If the target slot is occupied, swap the two elements
+ // and then continue processing the element that we just
+ // swapped into the old slot.
+ debug_assert_eq!(prev_ctrl, DELETED);
+ mem::swap(guard.bucket(new_i).as_mut(), item.as_mut());
+ continue 'inner;
+ }
+ }
+ }
+
+ guard.growth_left = bucket_mask_to_capacity(guard.bucket_mask) - guard.items;
+ mem::forget(guard);
+ }
+ }
+
+ /// Allocates a new table of a different size and moves the contents of the
+ /// current table into it.
+ fn resize(
+ &mut self,
+ capacity: usize,
+ hasher: impl Fn(&T) -> u64,
+ fallability: Fallibility,
+ ) -> Result<(), TryReserveError> {
+ unsafe {
+ debug_assert!(self.items <= capacity);
+
+ // Allocate and initialize the new table.
+ let mut new_table = Self::fallible_with_capacity(capacity, fallability)?;
+ new_table.growth_left -= self.items;
+ new_table.items = self.items;
+
+ // The hash function may panic, in which case we simply free the new
+ // table without dropping any elements that may have been copied into
+ // it.
+ //
+ // This guard is also used to free the old table on success, see
+ // the comment at the bottom of this function.
+ let mut new_table = guard(ManuallyDrop::new(new_table), |new_table| {
+ if !new_table.is_empty_singleton() {
+ new_table.free_buckets();
+ }
+ });
+
+ // Copy all elements to the new table.
+ for item in self.iter() {
+ // This may panic.
+ let hash = hasher(item.as_ref());
+
+ // We can use a simpler version of insert() here since:
+ // - there are no DELETED entries.
+ // - we know there is enough space in the table.
+ // - all elements are unique.
+ let index = new_table.find_insert_slot(hash);
+ new_table.set_ctrl(index, h2(hash));
+ new_table.bucket(index).copy_from_nonoverlapping(&item);
+ }
+
+ // We successfully copied all elements without panicking. Now replace
+ // self with the new table. The old table will have its memory freed but
+ // the items will not be dropped (since they have been moved into the
+ // new table).
+ mem::swap(self, &mut new_table);
+
+ Ok(())
+ }
+ }
+
+ /// Inserts a new element into the table, and returns its raw bucket.
+ ///
+ /// This does not check if the given element already exists in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(&mut self, hash: u64, value: T, hasher: impl Fn(&T) -> u64) -> Bucket<T> {
+ unsafe {
+ let mut index = self.find_insert_slot(hash);
+
+ // We can avoid growing the table once we have reached our load
+ // factor if we are replacing a tombstone. This works since the
+ // number of EMPTY slots does not change in this case.
+ let old_ctrl = *self.ctrl(index);
+ if unlikely(self.growth_left == 0 && special_is_empty(old_ctrl)) {
+ self.reserve(1, hasher);
+ index = self.find_insert_slot(hash);
+ }
+
+ let bucket = self.bucket(index);
+ self.growth_left -= special_is_empty(old_ctrl) as usize;
+ self.set_ctrl(index, h2(hash));
+ bucket.write(value);
+ self.items += 1;
+ bucket
+ }
+ }
+
+ /// Inserts a new element into the table, and returns a mutable reference to it.
+ ///
+ /// This does not check if the given element already exists in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert_entry(&mut self, hash: u64, value: T, hasher: impl Fn(&T) -> u64) -> &mut T {
+ unsafe { self.insert(hash, value, hasher).as_mut() }
+ }
+
+ /// Inserts a new element into the table, without growing the table.
+ ///
+ /// There must be enough space in the table to insert the new element.
+ ///
+ /// This does not check if the given element already exists in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[cfg(any(feature = "raw", feature = "rustc-internal-api"))]
+ pub fn insert_no_grow(&mut self, hash: u64, value: T) -> Bucket<T> {
+ unsafe {
+ let index = self.find_insert_slot(hash);
+ let bucket = self.bucket(index);
+
+ // If we are replacing a DELETED entry then we don't need to update
+ // the load counter.
+ let old_ctrl = *self.ctrl(index);
+ self.growth_left -= special_is_empty(old_ctrl) as usize;
+
+ self.set_ctrl(index, h2(hash));
+ bucket.write(value);
+ self.items += 1;
+ bucket
+ }
+ }
+
+ /// Temporary removes a bucket, applying the given function to the removed
+ /// element and optionally put back the returned value in the same bucket.
+ ///
+ /// Returns `true` if the bucket still contains an element
+ ///
+ /// This does not check if the given bucket is actually occupied.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn replace_bucket_with<F>(&mut self, bucket: Bucket<T>, f: F) -> bool
+ where
+ F: FnOnce(T) -> Option<T>,
+ {
+ let index = self.bucket_index(&bucket);
+ let old_ctrl = *self.ctrl(index);
+ debug_assert!(is_full(old_ctrl));
+ let old_growth_left = self.growth_left;
+ let item = self.remove(bucket);
+ if let Some(new_item) = f(item) {
+ self.growth_left = old_growth_left;
+ self.set_ctrl(index, old_ctrl);
+ self.items += 1;
+ self.bucket(index).write(new_item);
+ true
+ } else {
+ false
+ }
+ }
+
+ /// Searches for an element in the table.
+ #[inline]
+ pub fn find(&self, hash: u64, mut eq: impl FnMut(&T) -> bool) -> Option<Bucket<T>> {
+ unsafe {
+ for bucket in self.iter_hash(hash) {
+ let elm = bucket.as_ref();
+ if likely(eq(elm)) {
+ return Some(bucket);
+ }
+ }
+ None
+ }
+ }
+
+ /// Gets a reference to an element in the table.
+ #[inline]
+ pub fn get(&self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<&T> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.find(hash, eq) {
+ Some(bucket) => Some(unsafe { bucket.as_ref() }),
+ None => None,
+ }
+ }
+
+ /// Gets a mutable reference to an element in the table.
+ #[inline]
+ pub fn get_mut(&mut self, hash: u64, eq: impl FnMut(&T) -> bool) -> Option<&mut T> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.find(hash, eq) {
+ Some(bucket) => Some(unsafe { bucket.as_mut() }),
+ None => None,
+ }
+ }
+
+ /// Returns the number of elements the map can hold without reallocating.
+ ///
+ /// This number is a lower bound; the table might be able to hold
+ /// more, but is guaranteed to be able to hold at least this many.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn capacity(&self) -> usize {
+ self.items + self.growth_left
+ }
+
+ /// Returns the number of elements in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn len(&self) -> usize {
+ self.items
+ }
+
+ /// Returns the number of buckets in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn buckets(&self) -> usize {
+ self.bucket_mask + 1
+ }
+
+ /// Returns the number of control bytes in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn num_ctrl_bytes(&self) -> usize {
+ self.bucket_mask + 1 + Group::WIDTH
+ }
+
+ /// Returns whether this table points to the empty singleton with a capacity
+ /// of 0.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn is_empty_singleton(&self) -> bool {
+ self.bucket_mask == 0
+ }
+
+ /// Returns an iterator over every element in the table. It is up to
+ /// the caller to ensure that the `RawTable` outlives the `RawIter`.
+ /// Because we cannot make the `next` method unsafe on the `RawIter`
+ /// struct, we have to make the `iter` method unsafe.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn iter(&self) -> RawIter<T> {
+ let data = Bucket::from_base_index(self.data_end(), 0);
+ RawIter {
+ iter: RawIterRange::new(self.ctrl.as_ptr(), data, self.buckets()),
+ items: self.items,
+ }
+ }
+
+ /// Returns an iterator over occupied buckets that could match a given hash.
+ ///
+ /// In rare cases, the iterator may return a bucket with a different hash.
+ ///
+ /// It is up to the caller to ensure that the `RawTable` outlives the
+ /// `RawIterHash`. Because we cannot make the `next` method unsafe on the
+ /// `RawIterHash` struct, we have to make the `iter_hash` method unsafe.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn iter_hash(&self, hash: u64) -> RawIterHash<'_, T> {
+ RawIterHash::new(self, hash)
+ }
+
+ /// Returns an iterator which removes all elements from the table without
+ /// freeing the memory.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn drain(&mut self) -> RawDrain<'_, T> {
+ unsafe {
+ let iter = self.iter();
+ self.drain_iter_from(iter)
+ }
+ }
+
+ /// Returns an iterator which removes all elements from the table without
+ /// freeing the memory.
+ ///
+ /// Iteration starts at the provided iterator's current location.
+ ///
+ /// It is up to the caller to ensure that the iterator is valid for this
+ /// `RawTable` and covers all items that remain in the table.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub unsafe fn drain_iter_from(&mut self, iter: RawIter<T>) -> RawDrain<'_, T> {
+ debug_assert_eq!(iter.len(), self.len());
+ RawDrain {
+ iter,
+ table: ManuallyDrop::new(mem::replace(self, Self::new())),
+ orig_table: NonNull::from(self),
+ marker: PhantomData,
+ }
+ }
+
+ /// Returns an iterator which consumes all elements from the table.
+ ///
+ /// Iteration starts at the provided iterator's current location.
+ ///
+ /// It is up to the caller to ensure that the iterator is valid for this
+ /// `RawTable` and covers all items that remain in the table.
+ pub unsafe fn into_iter_from(self, iter: RawIter<T>) -> RawIntoIter<T> {
+ debug_assert_eq!(iter.len(), self.len());
+
+ let alloc = self.into_alloc();
+ RawIntoIter {
+ iter,
+ alloc,
+ marker: PhantomData,
+ }
+ }
+
+ /// Converts the table into a raw allocation. The contents of the table
+ /// should be dropped using a `RawIter` before freeing the allocation.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub(crate) fn into_alloc(self) -> Option<(NonNull<u8>, Layout)> {
+ let alloc = if self.is_empty_singleton() {
+ None
+ } else {
+ // Avoid `Option::unwrap_or_else` because it bloats LLVM IR.
+ let (layout, ctrl_offset) = match calculate_layout::<T>(self.buckets()) {
+ Some(lco) => lco,
+ None => unsafe { hint::unreachable_unchecked() },
+ };
+ Some((
+ unsafe { NonNull::new_unchecked(self.ctrl.as_ptr().sub(ctrl_offset)) },
+ layout,
+ ))
+ };
+ mem::forget(self);
+ alloc
+ }
+}
+
+unsafe impl<T> Send for RawTable<T> where T: Send {}
+unsafe impl<T> Sync for RawTable<T> where T: Sync {}
+
+impl<T: Clone> Clone for RawTable<T> {
+ fn clone(&self) -> Self {
+ if self.is_empty_singleton() {
+ Self::new()
+ } else {
+ unsafe {
+ let mut new_table = ManuallyDrop::new(
+ // Avoid `Result::ok_or_else` because it bloats LLVM IR.
+ match Self::new_uninitialized(self.buckets(), Fallibility::Infallible) {
+ Ok(table) => table,
+ Err(_) => hint::unreachable_unchecked(),
+ },
+ );
+
+ new_table.clone_from_spec(self, |new_table| {
+ // We need to free the memory allocated for the new table.
+ new_table.free_buckets();
+ });
+
+ // Return the newly created table.
+ ManuallyDrop::into_inner(new_table)
+ }
+ }
+ }
+
+ fn clone_from(&mut self, source: &Self) {
+ if source.is_empty_singleton() {
+ *self = Self::new();
+ } else {
+ unsafe {
+ // First, drop all our elements without clearing the control bytes.
+ if mem::needs_drop::<T>() && self.len() != 0 {
+ for item in self.iter() {
+ item.drop();
+ }
+ }
+
+ // If necessary, resize our table to match the source.
+ if self.buckets() != source.buckets() {
+ // Skip our drop by using ptr::write.
+ if !self.is_empty_singleton() {
+ self.free_buckets();
+ }
+ (self as *mut Self).write(
+ // Avoid `Result::unwrap_or_else` because it bloats LLVM IR.
+ match Self::new_uninitialized(source.buckets(), Fallibility::Infallible) {
+ Ok(table) => table,
+ Err(_) => hint::unreachable_unchecked(),
+ },
+ );
+ }
+
+ self.clone_from_spec(source, |self_| {
+ // We need to leave the table in an empty state.
+ self_.clear_no_drop()
+ });
+ }
+ }
+ }
+}
+
+/// Specialization of `clone_from` for `Copy` types
+trait RawTableClone {
+ unsafe fn clone_from_spec(&mut self, source: &Self, on_panic: impl FnMut(&mut Self));
+}
+impl<T: Clone> RawTableClone for RawTable<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ default_fn! {
+ unsafe fn clone_from_spec(&mut self, source: &Self, on_panic: impl FnMut(&mut Self)) {
+ self.clone_from_impl(source, on_panic);
+ }
+ }
+}
+#[cfg(feature = "nightly")]
+impl<T: Copy> RawTableClone for RawTable<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn clone_from_spec(&mut self, source: &Self, _on_panic: impl FnMut(&mut Self)) {
+ source
+ .ctrl(0)
+ .copy_to_nonoverlapping(self.ctrl(0), self.num_ctrl_bytes());
+ source
+ .data_start()
+ .copy_to_nonoverlapping(self.data_start(), self.buckets());
+
+ self.items = source.items;
+ self.growth_left = source.growth_left;
+ }
+}
+
+impl<T: Clone> RawTable<T> {
+ /// Common code for clone and clone_from. Assumes `self.buckets() == source.buckets()`.
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn clone_from_impl(&mut self, source: &Self, mut on_panic: impl FnMut(&mut Self)) {
+ // Copy the control bytes unchanged. We do this in a single pass
+ source
+ .ctrl(0)
+ .copy_to_nonoverlapping(self.ctrl(0), self.num_ctrl_bytes());
+
+ // The cloning of elements may panic, in which case we need
+ // to make sure we drop only the elements that have been
+ // cloned so far.
+ let mut guard = guard((0, &mut *self), |(index, self_)| {
+ if mem::needs_drop::<T>() && self_.len() != 0 {
+ for i in 0..=*index {
+ if is_full(*self_.ctrl(i)) {
+ self_.bucket(i).drop();
+ }
+ }
+ }
+
+ // Depending on whether we were called from clone or clone_from, we
+ // either need to free the memory for the destination table or just
+ // clear the control bytes.
+ on_panic(self_);
+ });
+
+ for from in source.iter() {
+ let index = source.bucket_index(&from);
+ let to = guard.1.bucket(index);
+ to.write(from.as_ref().clone());
+
+ // Update the index in case we need to unwind.
+ guard.0 = index;
+ }
+
+ // Successfully cloned all items, no need to clean up.
+ mem::forget(guard);
+
+ self.items = source.items;
+ self.growth_left = source.growth_left;
+ }
+
+ /// Variant of `clone_from` to use when a hasher is available.
+ #[cfg(feature = "raw")]
+ pub fn clone_from_with_hasher(&mut self, source: &Self, hasher: impl Fn(&T) -> u64) {
+ // If we have enough capacity in the table, just clear it and insert
+ // elements one by one. We don't do this if we have the same number of
+ // buckets as the source since we can just copy the contents directly
+ // in that case.
+ if self.buckets() != source.buckets()
+ && bucket_mask_to_capacity(self.bucket_mask) >= source.len()
+ {
+ self.clear();
+
+ let guard_self = guard(&mut *self, |self_| {
+ // Clear the partially copied table if a panic occurs, otherwise
+ // items and growth_left will be out of sync with the contents
+ // of the table.
+ self_.clear();
+ });
+
+ unsafe {
+ for item in source.iter() {
+ // This may panic.
+ let item = item.as_ref().clone();
+ let hash = hasher(&item);
+
+ // We can use a simpler version of insert() here since:
+ // - there are no DELETED entries.
+ // - we know there is enough space in the table.
+ // - all elements are unique.
+ let index = guard_self.find_insert_slot(hash);
+ guard_self.set_ctrl(index, h2(hash));
+ guard_self.bucket(index).write(item);
+ }
+ }
+
+ // Successfully cloned all items, no need to clean up.
+ mem::forget(guard_self);
+
+ self.items = source.items;
+ self.growth_left -= source.items;
+ } else {
+ self.clone_from(source);
+ }
+ }
+}
+
+#[cfg(feature = "nightly")]
+unsafe impl<#[may_dangle] T> Drop for RawTable<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ if !self.is_empty_singleton() {
+ unsafe {
+ if mem::needs_drop::<T>() && self.len() != 0 {
+ for item in self.iter() {
+ item.drop();
+ }
+ }
+ self.free_buckets();
+ }
+ }
+ }
+}
+#[cfg(not(feature = "nightly"))]
+impl<T> Drop for RawTable<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ if !self.is_empty_singleton() {
+ unsafe {
+ if mem::needs_drop::<T>() && self.len() != 0 {
+ for item in self.iter() {
+ item.drop();
+ }
+ }
+ self.free_buckets();
+ }
+ }
+ }
+}
+
+impl<T> IntoIterator for RawTable<T> {
+ type Item = T;
+ type IntoIter = RawIntoIter<T>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_iter(self) -> RawIntoIter<T> {
+ unsafe {
+ let iter = self.iter();
+ self.into_iter_from(iter)
+ }
+ }
+}
+
+/// Iterator over a sub-range of a table. Unlike `RawIter` this iterator does
+/// not track an item count.
+pub(crate) struct RawIterRange<T> {
+ // Mask of full buckets in the current group. Bits are cleared from this
+ // mask as each element is processed.
+ current_group: BitMask,
+
+ // Pointer to the buckets for the current group.
+ data: Bucket<T>,
+
+ // Pointer to the next group of control bytes,
+ // Must be aligned to the group size.
+ next_ctrl: *const u8,
+
+ // Pointer one past the last control byte of this range.
+ end: *const u8,
+}
+
+impl<T> RawIterRange<T> {
+ /// Returns a `RawIterRange` covering a subset of a table.
+ ///
+ /// The control byte address must be aligned to the group size.
+ #[cfg_attr(feature = "inline-more", inline)]
+ unsafe fn new(ctrl: *const u8, data: Bucket<T>, len: usize) -> Self {
+ debug_assert_ne!(len, 0);
+ debug_assert_eq!(ctrl as usize % Group::WIDTH, 0);
+ let end = ctrl.add(len);
+
+ // Load the first group and advance ctrl to point to the next group
+ let current_group = Group::load_aligned(ctrl).match_full();
+ let next_ctrl = ctrl.add(Group::WIDTH);
+
+ Self {
+ current_group,
+ data,
+ next_ctrl,
+ end,
+ }
+ }
+
+ /// Splits a `RawIterRange` into two halves.
+ ///
+ /// Returns `None` if the remaining range is smaller than or equal to the
+ /// group width.
+ #[cfg_attr(feature = "inline-more", inline)]
+ #[cfg(feature = "rayon")]
+ pub(crate) fn split(mut self) -> (Self, Option<RawIterRange<T>>) {
+ unsafe {
+ if self.end <= self.next_ctrl {
+ // Nothing to split if the group that we are current processing
+ // is the last one.
+ (self, None)
+ } else {
+ // len is the remaining number of elements after the group that
+ // we are currently processing. It must be a multiple of the
+ // group size (small tables are caught by the check above).
+ let len = offset_from(self.end, self.next_ctrl);
+ debug_assert_eq!(len % Group::WIDTH, 0);
+
+ // Split the remaining elements into two halves, but round the
+ // midpoint down in case there is an odd number of groups
+ // remaining. This ensures that:
+ // - The tail is at least 1 group long.
+ // - The split is roughly even considering we still have the
+ // current group to process.
+ let mid = (len / 2) & !(Group::WIDTH - 1);
+
+ let tail = Self::new(
+ self.next_ctrl.add(mid),
+ self.data.next_n(Group::WIDTH).next_n(mid),
+ len - mid,
+ );
+ debug_assert_eq!(
+ self.data.next_n(Group::WIDTH).next_n(mid).ptr,
+ tail.data.ptr
+ );
+ debug_assert_eq!(self.end, tail.end);
+ self.end = self.next_ctrl.add(mid);
+ debug_assert_eq!(self.end.add(Group::WIDTH), tail.next_ctrl);
+ (self, Some(tail))
+ }
+ }
+ }
+}
+
+// We make raw iterators unconditionally Send and Sync, and let the PhantomData
+// in the actual iterator implementations determine the real Send/Sync bounds.
+unsafe impl<T> Send for RawIterRange<T> {}
+unsafe impl<T> Sync for RawIterRange<T> {}
+
+impl<T> Clone for RawIterRange<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Self {
+ data: self.data.clone(),
+ next_ctrl: self.next_ctrl,
+ current_group: self.current_group,
+ end: self.end,
+ }
+ }
+}
+
+impl<T> Iterator for RawIterRange<T> {
+ type Item = Bucket<T>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<Bucket<T>> {
+ unsafe {
+ loop {
+ if let Some(index) = self.current_group.lowest_set_bit() {
+ self.current_group = self.current_group.remove_lowest_bit();
+ return Some(self.data.next_n(index));
+ }
+
+ if self.next_ctrl >= self.end {
+ return None;
+ }
+
+ // We might read past self.end up to the next group boundary,
+ // but this is fine because it only occurs on tables smaller
+ // than the group size where the trailing control bytes are all
+ // EMPTY. On larger tables self.end is guaranteed to be aligned
+ // to the group size (since tables are power-of-two sized).
+ self.current_group = Group::load_aligned(self.next_ctrl).match_full();
+ self.data = self.data.next_n(Group::WIDTH);
+ self.next_ctrl = self.next_ctrl.add(Group::WIDTH);
+ }
+ }
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ // We don't have an item count, so just guess based on the range size.
+ (
+ 0,
+ Some(unsafe { offset_from(self.end, self.next_ctrl) + Group::WIDTH }),
+ )
+ }
+}
+
+impl<T> FusedIterator for RawIterRange<T> {}
+
+/// Iterator which returns a raw pointer to every full bucket in the table.
+///
+/// For maximum flexibility this iterator is not bound by a lifetime, but you
+/// must observe several rules when using it:
+/// - You must not free the hash table while iterating (including via growing/shrinking).
+/// - It is fine to erase a bucket that has been yielded by the iterator.
+/// - Erasing a bucket that has not yet been yielded by the iterator may still
+/// result in the iterator yielding that bucket (unless `reflect_remove` is called).
+/// - It is unspecified whether an element inserted after the iterator was
+/// created will be yielded by that iterator (unless `reflect_insert` is called).
+/// - The order in which the iterator yields bucket is unspecified and may
+/// change in the future.
+pub struct RawIter<T> {
+ pub(crate) iter: RawIterRange<T>,
+ items: usize,
+}
+
+impl<T> RawIter<T> {
+ /// Refresh the iterator so that it reflects a removal from the given bucket.
+ ///
+ /// For the iterator to remain valid, this method must be called once
+ /// for each removed bucket before `next` is called again.
+ ///
+ /// This method should be called _before_ the removal is made. It is not necessary to call this
+ /// method if you are removing an item that this iterator yielded in the past.
+ #[cfg(feature = "raw")]
+ pub fn reflect_remove(&mut self, b: &Bucket<T>) {
+ self.reflect_toggle_full(b, false);
+ }
+
+ /// Refresh the iterator so that it reflects an insertion into the given bucket.
+ ///
+ /// For the iterator to remain valid, this method must be called once
+ /// for each insert before `next` is called again.
+ ///
+ /// This method does not guarantee that an insertion of a bucket witha greater
+ /// index than the last one yielded will be reflected in the iterator.
+ ///
+ /// This method should be called _after_ the given insert is made.
+ #[cfg(feature = "raw")]
+ pub fn reflect_insert(&mut self, b: &Bucket<T>) {
+ self.reflect_toggle_full(b, true);
+ }
+
+ /// Refresh the iterator so that it reflects a change to the state of the given bucket.
+ #[cfg(feature = "raw")]
+ fn reflect_toggle_full(&mut self, b: &Bucket<T>, is_insert: bool) {
+ unsafe {
+ if b.as_ptr() > self.iter.data.as_ptr() {
+ // The iterator has already passed the bucket's group.
+ // So the toggle isn't relevant to this iterator.
+ return;
+ }
+
+ if self.iter.next_ctrl < self.iter.end
+ && b.as_ptr() <= self.iter.data.next_n(Group::WIDTH).as_ptr()
+ {
+ // The iterator has not yet reached the bucket's group.
+ // We don't need to reload anything, but we do need to adjust the item count.
+
+ if cfg!(debug_assertions) {
+ // Double-check that the user isn't lying to us by checking the bucket state.
+ // To do that, we need to find its control byte. We know that self.iter.data is
+ // at self.iter.next_ctrl - Group::WIDTH, so we work from there:
+ let offset = offset_from(self.iter.data.as_ptr(), b.as_ptr());
+ let ctrl = self.iter.next_ctrl.sub(Group::WIDTH).add(offset);
+ // This method should be called _before_ a removal, or _after_ an insert,
+ // so in both cases the ctrl byte should indicate that the bucket is full.
+ assert!(is_full(*ctrl));
+ }
+
+ if is_insert {
+ self.items += 1;
+ } else {
+ self.items -= 1;
+ }
+
+ return;
+ }
+
+ // The iterator is at the bucket group that the toggled bucket is in.
+ // We need to do two things:
+ //
+ // - Determine if the iterator already yielded the toggled bucket.
+ // If it did, we're done.
+ // - Otherwise, update the iterator cached group so that it won't
+ // yield a to-be-removed bucket, or _will_ yield a to-be-added bucket.
+ // We'll also need ot update the item count accordingly.
+ if let Some(index) = self.iter.current_group.lowest_set_bit() {
+ let next_bucket = self.iter.data.next_n(index);
+ if b.as_ptr() > next_bucket.as_ptr() {
+ // The toggled bucket is "before" the bucket the iterator would yield next. We
+ // therefore don't need to do anything --- the iterator has already passed the
+ // bucket in question.
+ //
+ // The item count must already be correct, since a removal or insert "prior" to
+ // the iterator's position wouldn't affect the item count.
+ } else {
+ // The removed bucket is an upcoming bucket. We need to make sure it does _not_
+ // get yielded, and also that it's no longer included in the item count.
+ //
+ // NOTE: We can't just reload the group here, both since that might reflect
+ // inserts we've already passed, and because that might inadvertently unset the
+ // bits for _other_ removals. If we do that, we'd have to also decrement the
+ // item count for those other bits that we unset. But the presumably subsequent
+ // call to reflect for those buckets might _also_ decrement the item count.
+ // Instead, we _just_ flip the bit for the particular bucket the caller asked
+ // us to reflect.
+ let our_bit = offset_from(self.iter.data.as_ptr(), b.as_ptr());
+ let was_full = self.iter.current_group.flip(our_bit);
+ debug_assert_ne!(was_full, is_insert);
+
+ if is_insert {
+ self.items += 1;
+ } else {
+ self.items -= 1;
+ }
+
+ if cfg!(debug_assertions) {
+ if b.as_ptr() == next_bucket.as_ptr() {
+ // The removed bucket should no longer be next
+ debug_assert_ne!(self.iter.current_group.lowest_set_bit(), Some(index));
+ } else {
+ // We should not have changed what bucket comes next.
+ debug_assert_eq!(self.iter.current_group.lowest_set_bit(), Some(index));
+ }
+ }
+ }
+ } else {
+ // We must have already iterated past the removed item.
+ }
+ }
+ }
+}
+
+impl<T> Clone for RawIter<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Self {
+ iter: self.iter.clone(),
+ items: self.items,
+ }
+ }
+}
+
+impl<T> Iterator for RawIter<T> {
+ type Item = Bucket<T>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<Bucket<T>> {
+ if let Some(b) = self.iter.next() {
+ self.items -= 1;
+ Some(b)
+ } else {
+ // We don't check against items == 0 here to allow the
+ // compiler to optimize away the item count entirely if the
+ // iterator length is never queried.
+ debug_assert_eq!(self.items, 0);
+ None
+ }
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ (self.items, Some(self.items))
+ }
+}
+
+impl<T> ExactSizeIterator for RawIter<T> {}
+impl<T> FusedIterator for RawIter<T> {}
+
+/// Iterator which consumes a table and returns elements.
+pub struct RawIntoIter<T> {
+ iter: RawIter<T>,
+ alloc: Option<(NonNull<u8>, Layout)>,
+ marker: PhantomData<T>,
+}
+
+impl<T> RawIntoIter<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn iter(&self) -> RawIter<T> {
+ self.iter.clone()
+ }
+}
+
+unsafe impl<T> Send for RawIntoIter<T> where T: Send {}
+unsafe impl<T> Sync for RawIntoIter<T> where T: Sync {}
+
+#[cfg(feature = "nightly")]
+unsafe impl<#[may_dangle] T> Drop for RawIntoIter<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ unsafe {
+ // Drop all remaining elements
+ if mem::needs_drop::<T>() && self.iter.len() != 0 {
+ while let Some(item) = self.iter.next() {
+ item.drop();
+ }
+ }
+
+ // Free the table
+ if let Some((ptr, layout)) = self.alloc {
+ dealloc(ptr.as_ptr(), layout);
+ }
+ }
+ }
+}
+#[cfg(not(feature = "nightly"))]
+impl<T> Drop for RawIntoIter<T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ unsafe {
+ // Drop all remaining elements
+ if mem::needs_drop::<T>() && self.iter.len() != 0 {
+ while let Some(item) = self.iter.next() {
+ item.drop();
+ }
+ }
+
+ // Free the table
+ if let Some((ptr, layout)) = self.alloc {
+ dealloc(ptr.as_ptr(), layout);
+ }
+ }
+ }
+}
+
+impl<T> Iterator for RawIntoIter<T> {
+ type Item = T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<T> {
+ unsafe { Some(self.iter.next()?.read()) }
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+
+impl<T> ExactSizeIterator for RawIntoIter<T> {}
+impl<T> FusedIterator for RawIntoIter<T> {}
+
+/// Iterator which consumes elements without freeing the table storage.
+pub struct RawDrain<'a, T> {
+ iter: RawIter<T>,
+
+ // The table is moved into the iterator for the duration of the drain. This
+ // ensures that an empty table is left if the drain iterator is leaked
+ // without dropping.
+ table: ManuallyDrop<RawTable<T>>,
+ orig_table: NonNull<RawTable<T>>,
+
+ // We don't use a &'a mut RawTable<T> because we want RawDrain to be
+ // covariant over T.
+ marker: PhantomData<&'a RawTable<T>>,
+}
+
+impl<T> RawDrain<'_, T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn iter(&self) -> RawIter<T> {
+ self.iter.clone()
+ }
+}
+
+unsafe impl<T> Send for RawDrain<'_, T> where T: Send {}
+unsafe impl<T> Sync for RawDrain<'_, T> where T: Sync {}
+
+impl<T> Drop for RawDrain<'_, T> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ unsafe {
+ // Drop all remaining elements. Note that this may panic.
+ if mem::needs_drop::<T>() && self.iter.len() != 0 {
+ while let Some(item) = self.iter.next() {
+ item.drop();
+ }
+ }
+
+ // Reset the contents of the table now that all elements have been
+ // dropped.
+ self.table.clear_no_drop();
+
+ // Move the now empty table back to its original location.
+ self.orig_table
+ .as_ptr()
+ .copy_from_nonoverlapping(&*self.table, 1);
+ }
+ }
+}
+
+impl<T> Iterator for RawDrain<'_, T> {
+ type Item = T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<T> {
+ unsafe {
+ let item = self.iter.next()?;
+ Some(item.read())
+ }
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+
+impl<T> ExactSizeIterator for RawDrain<'_, T> {}
+impl<T> FusedIterator for RawDrain<'_, T> {}
+
+/// Iterator over occupied buckets that could match a given hash.
+///
+/// In rare cases, the iterator may return a bucket with a different hash.
+pub struct RawIterHash<'a, T> {
+ table: &'a RawTable<T>,
+
+ // The top 7 bits of the hash.
+ h2_hash: u8,
+
+ // The sequence of groups to probe in the search.
+ probe_seq: ProbeSeq,
+
+ // The current group and its position.
+ pos: usize,
+ group: Group,
+
+ // The elements within the group with a matching h2-hash.
+ bitmask: BitMaskIter,
+}
+
+impl<'a, T> RawIterHash<'a, T> {
+ fn new(table: &'a RawTable<T>, hash: u64) -> Self {
+ unsafe {
+ let h2_hash = h2(hash);
+ let mut probe_seq = table.probe_seq(hash);
+ let pos = probe_seq.next().unwrap();
+ let group = Group::load(table.ctrl(pos));
+ let bitmask = group.match_byte(h2_hash).into_iter();
+
+ RawIterHash {
+ table,
+ h2_hash,
+ probe_seq,
+ pos,
+ group,
+ bitmask,
+ }
+ }
+ }
+}
+
+impl<'a, T> Iterator for RawIterHash<'a, T> {
+ type Item = Bucket<T>;
+
+ fn next(&mut self) -> Option<Bucket<T>> {
+ unsafe {
+ loop {
+ if let Some(bit) = self.bitmask.next() {
+ let index = (self.pos + bit) & self.table.bucket_mask;
+ let bucket = self.table.bucket(index);
+ return Some(bucket);
+ }
+ if likely(self.group.match_empty().any_bit_set()) {
+ return None;
+ }
+ self.pos = self.probe_seq.next().unwrap();
+ self.group = Group::load(self.table.ctrl(self.pos));
+ self.bitmask = self.group.match_byte(self.h2_hash).into_iter();
+ }
+ }
+ }
+}
diff --git a/src/raw/sse2.rs b/src/raw/sse2.rs
new file mode 100644
index 0000000..a27bc09
--- /dev/null
+++ b/src/raw/sse2.rs
@@ -0,0 +1,144 @@
+use super::bitmask::BitMask;
+use super::EMPTY;
+use core::mem;
+
+#[cfg(target_arch = "x86")]
+use core::arch::x86;
+#[cfg(target_arch = "x86_64")]
+use core::arch::x86_64 as x86;
+
+pub type BitMaskWord = u16;
+pub const BITMASK_STRIDE: usize = 1;
+pub const BITMASK_MASK: BitMaskWord = 0xffff;
+
+/// Abstraction over a group of control bytes which can be scanned in
+/// parallel.
+///
+/// This implementation uses a 128-bit SSE value.
+#[derive(Copy, Clone)]
+pub struct Group(x86::__m128i);
+
+// FIXME: https://github.com/rust-lang/rust-clippy/issues/3859
+#[allow(clippy::use_self)]
+impl Group {
+ /// Number of bytes in the group.
+ pub const WIDTH: usize = mem::size_of::<Self>();
+
+ /// Returns a full group of empty bytes, suitable for use as the initial
+ /// value for an empty hash table.
+ ///
+ /// This is guaranteed to be aligned to the group size.
+ pub const fn static_empty() -> &'static [u8; Group::WIDTH] {
+ #[repr(C)]
+ struct AlignedBytes {
+ _align: [Group; 0],
+ bytes: [u8; Group::WIDTH],
+ };
+ const ALIGNED_BYTES: AlignedBytes = AlignedBytes {
+ _align: [],
+ bytes: [EMPTY; Group::WIDTH],
+ };
+ &ALIGNED_BYTES.bytes
+ }
+
+ /// Loads a group of bytes starting at the given address.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)] // unaligned load
+ pub unsafe fn load(ptr: *const u8) -> Self {
+ Group(x86::_mm_loadu_si128(ptr as *const _))
+ }
+
+ /// Loads a group of bytes starting at the given address, which must be
+ /// aligned to `mem::align_of::<Group>()`.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)]
+ pub unsafe fn load_aligned(ptr: *const u8) -> Self {
+ // FIXME: use align_offset once it stabilizes
+ debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0);
+ Group(x86::_mm_load_si128(ptr as *const _))
+ }
+
+ /// Stores the group of bytes to the given address, which must be
+ /// aligned to `mem::align_of::<Group>()`.
+ #[inline]
+ #[allow(clippy::cast_ptr_alignment)]
+ pub unsafe fn store_aligned(self, ptr: *mut u8) {
+ // FIXME: use align_offset once it stabilizes
+ debug_assert_eq!(ptr as usize & (mem::align_of::<Self>() - 1), 0);
+ x86::_mm_store_si128(ptr as *mut _, self.0);
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which have
+ /// the given value.
+ #[inline]
+ pub fn match_byte(self, byte: u8) -> BitMask {
+ #[allow(
+ clippy::cast_possible_wrap, // byte: u8 as i8
+ // byte: i32 as u16
+ // note: _mm_movemask_epi8 returns a 16-bit mask in a i32, the
+ // upper 16-bits of the i32 are zeroed:
+ clippy::cast_sign_loss,
+ clippy::cast_possible_truncation
+ )]
+ unsafe {
+ let cmp = x86::_mm_cmpeq_epi8(self.0, x86::_mm_set1_epi8(byte as i8));
+ BitMask(x86::_mm_movemask_epi8(cmp) as u16)
+ }
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which are
+ /// `EMPTY`.
+ #[inline]
+ pub fn match_empty(self) -> BitMask {
+ self.match_byte(EMPTY)
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which are
+ /// `EMPTY` or `DELETED`.
+ #[inline]
+ pub fn match_empty_or_deleted(self) -> BitMask {
+ #[allow(
+ // byte: i32 as u16
+ // note: _mm_movemask_epi8 returns a 16-bit mask in a i32, the
+ // upper 16-bits of the i32 are zeroed:
+ clippy::cast_sign_loss,
+ clippy::cast_possible_truncation
+ )]
+ unsafe {
+ // A byte is EMPTY or DELETED iff the high bit is set
+ BitMask(x86::_mm_movemask_epi8(self.0) as u16)
+ }
+ }
+
+ /// Returns a `BitMask` indicating all bytes in the group which are full.
+ #[inline]
+ pub fn match_full(&self) -> BitMask {
+ self.match_empty_or_deleted().invert()
+ }
+
+ /// Performs the following transformation on all bytes in the group:
+ /// - `EMPTY => EMPTY`
+ /// - `DELETED => EMPTY`
+ /// - `FULL => DELETED`
+ #[inline]
+ pub fn convert_special_to_empty_and_full_to_deleted(self) -> Self {
+ // Map high_bit = 1 (EMPTY or DELETED) to 1111_1111
+ // and high_bit = 0 (FULL) to 1000_0000
+ //
+ // Here's this logic expanded to concrete values:
+ // let special = 0 > byte = 1111_1111 (true) or 0000_0000 (false)
+ // 1111_1111 | 1000_0000 = 1111_1111
+ // 0000_0000 | 1000_0000 = 1000_0000
+ #[allow(
+ clippy::cast_possible_wrap, // byte: 0x80_u8 as i8
+ )]
+ unsafe {
+ let zero = x86::_mm_setzero_si128();
+ let special = x86::_mm_cmpgt_epi8(zero, self.0);
+ Group(x86::_mm_or_si128(
+ special,
+ x86::_mm_set1_epi8(0x80_u8 as i8),
+ ))
+ }
+ }
+}
diff --git a/src/rustc_entry.rs b/src/rustc_entry.rs
new file mode 100644
index 0000000..b6ea7bc
--- /dev/null
+++ b/src/rustc_entry.rs
@@ -0,0 +1,618 @@
+use self::RustcEntry::*;
+use crate::map::{make_hash, Drain, HashMap, IntoIter, Iter, IterMut};
+use crate::raw::{Bucket, RawTable};
+use core::fmt::{self, Debug};
+use core::hash::{BuildHasher, Hash};
+use core::mem;
+
+impl<K, V, S> HashMap<K, V, S>
+where
+ K: Eq + Hash,
+ S: BuildHasher,
+{
+ /// Gets the given key's corresponding entry in the map for in-place manipulation.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut letters = HashMap::new();
+ ///
+ /// for ch in "a short treatise on fungi".chars() {
+ /// let counter = letters.rustc_entry(ch).or_insert(0);
+ /// *counter += 1;
+ /// }
+ ///
+ /// assert_eq!(letters[&'s'], 2);
+ /// assert_eq!(letters[&'t'], 3);
+ /// assert_eq!(letters[&'u'], 1);
+ /// assert_eq!(letters.get(&'y'), None);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn rustc_entry(&mut self, key: K) -> RustcEntry<'_, K, V> {
+ let hash = make_hash(&self.hash_builder, &key);
+ if let Some(elem) = self.table.find(hash, |q| q.0.eq(&key)) {
+ RustcEntry::Occupied(RustcOccupiedEntry {
+ key: Some(key),
+ elem,
+ table: &mut self.table,
+ })
+ } else {
+ // Ideally we would put this in VacantEntry::insert, but Entry is not
+ // generic over the BuildHasher and adding a generic parameter would be
+ // a breaking change.
+ self.reserve(1);
+
+ RustcEntry::Vacant(RustcVacantEntry {
+ hash,
+ key,
+ table: &mut self.table,
+ })
+ }
+ }
+}
+
+/// A view into a single entry in a map, which may either be vacant or occupied.
+///
+/// This `enum` is constructed from the [`entry`] method on [`HashMap`].
+///
+/// [`HashMap`]: struct.HashMap.html
+/// [`entry`]: struct.HashMap.html#method.rustc_entry
+pub enum RustcEntry<'a, K, V> {
+ /// An occupied entry.
+ Occupied(RustcOccupiedEntry<'a, K, V>),
+
+ /// A vacant entry.
+ Vacant(RustcVacantEntry<'a, K, V>),
+}
+
+impl<K: Debug, V: Debug> Debug for RustcEntry<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match *self {
+ Vacant(ref v) => f.debug_tuple("Entry").field(v).finish(),
+ Occupied(ref o) => f.debug_tuple("Entry").field(o).finish(),
+ }
+ }
+}
+
+/// A view into an occupied entry in a `HashMap`.
+/// It is part of the [`RustcEntry`] enum.
+///
+/// [`RustcEntry`]: enum.RustcEntry.html
+pub struct RustcOccupiedEntry<'a, K, V> {
+ key: Option<K>,
+ elem: Bucket<(K, V)>,
+ table: &'a mut RawTable<(K, V)>,
+}
+
+unsafe impl<K, V> Send for RustcOccupiedEntry<'_, K, V>
+where
+ K: Send,
+ V: Send,
+{
+}
+unsafe impl<K, V> Sync for RustcOccupiedEntry<'_, K, V>
+where
+ K: Sync,
+ V: Sync,
+{
+}
+
+impl<K: Debug, V: Debug> Debug for RustcOccupiedEntry<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_struct("OccupiedEntry")
+ .field("key", self.key())
+ .field("value", self.get())
+ .finish()
+ }
+}
+
+/// A view into a vacant entry in a `HashMap`.
+/// It is part of the [`RustcEntry`] enum.
+///
+/// [`RustcEntry`]: enum.RustcEntry.html
+pub struct RustcVacantEntry<'a, K, V> {
+ hash: u64,
+ key: K,
+ table: &'a mut RawTable<(K, V)>,
+}
+
+impl<K: Debug, V> Debug for RustcVacantEntry<'_, K, V> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_tuple("VacantEntry").field(self.key()).finish()
+ }
+}
+
+impl<'a, K, V> RustcEntry<'a, K, V> {
+ /// Sets the value of the entry, and returns a RustcOccupiedEntry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// let entry = map.entry("horseyland").insert(37);
+ ///
+ /// assert_eq!(entry.key(), &"horseyland");
+ /// ```
+ pub fn insert(self, value: V) -> RustcOccupiedEntry<'a, K, V> {
+ match self {
+ Vacant(entry) => entry.insert_entry(value),
+ Occupied(mut entry) => {
+ entry.insert(value);
+ entry
+ }
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the default if empty, and returns
+ /// a mutable reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// map.rustc_entry("poneyland").or_insert(3);
+ /// assert_eq!(map["poneyland"], 3);
+ ///
+ /// *map.rustc_entry("poneyland").or_insert(10) *= 2;
+ /// assert_eq!(map["poneyland"], 6);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert(self, default: V) -> &'a mut V
+ where
+ K: Hash,
+ {
+ match self {
+ Occupied(entry) => entry.into_mut(),
+ Vacant(entry) => entry.insert(default),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the result of the default function if empty,
+ /// and returns a mutable reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, String> = HashMap::new();
+ /// let s = "hoho".to_string();
+ ///
+ /// map.rustc_entry("poneyland").or_insert_with(|| s);
+ ///
+ /// assert_eq!(map["poneyland"], "hoho".to_string());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V
+ where
+ K: Hash,
+ {
+ match self {
+ Occupied(entry) => entry.into_mut(),
+ Vacant(entry) => entry.insert(default()),
+ }
+ }
+
+ /// Returns a reference to this entry's key.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ match *self {
+ Occupied(ref entry) => entry.key(),
+ Vacant(ref entry) => entry.key(),
+ }
+ }
+
+ /// Provides in-place mutable access to an occupied entry before any
+ /// potential inserts into the map.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// map.rustc_entry("poneyland")
+ /// .and_modify(|e| { *e += 1 })
+ /// .or_insert(42);
+ /// assert_eq!(map["poneyland"], 42);
+ ///
+ /// map.rustc_entry("poneyland")
+ /// .and_modify(|e| { *e += 1 })
+ /// .or_insert(42);
+ /// assert_eq!(map["poneyland"], 43);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn and_modify<F>(self, f: F) -> Self
+ where
+ F: FnOnce(&mut V),
+ {
+ match self {
+ Occupied(mut entry) => {
+ f(entry.get_mut());
+ Occupied(entry)
+ }
+ Vacant(entry) => Vacant(entry),
+ }
+ }
+}
+
+impl<'a, K, V: Default> RustcEntry<'a, K, V> {
+ /// Ensures a value is in the entry by inserting the default value if empty,
+ /// and returns a mutable reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # fn main() {
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, Option<u32>> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_default();
+ ///
+ /// assert_eq!(map["poneyland"], None);
+ /// # }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn or_default(self) -> &'a mut V
+ where
+ K: Hash,
+ {
+ match self {
+ Occupied(entry) => entry.into_mut(),
+ Vacant(entry) => entry.insert(Default::default()),
+ }
+ }
+}
+
+impl<'a, K, V> RustcOccupiedEntry<'a, K, V> {
+ /// Gets a reference to the key in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ /// assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ unsafe { &self.elem.as_ref().0 }
+ }
+
+ /// Take the ownership of the key and value from the map.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ ///
+ /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") {
+ /// // We delete the entry from the map.
+ /// o.remove_entry();
+ /// }
+ ///
+ /// assert_eq!(map.contains_key("poneyland"), false);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove_entry(self) -> (K, V) {
+ unsafe { self.table.remove(self.elem) }
+ }
+
+ /// Gets a reference to the value in the entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ ///
+ /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") {
+ /// assert_eq!(o.get(), &12);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get(&self) -> &V {
+ unsafe { &self.elem.as_ref().1 }
+ }
+
+ /// Gets a mutable reference to the value in the entry.
+ ///
+ /// If you need a reference to the `RustcOccupiedEntry` which may outlive the
+ /// destruction of the `RustcEntry` value, see [`into_mut`].
+ ///
+ /// [`into_mut`]: #method.into_mut
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ ///
+ /// assert_eq!(map["poneyland"], 12);
+ /// if let RustcEntry::Occupied(mut o) = map.rustc_entry("poneyland") {
+ /// *o.get_mut() += 10;
+ /// assert_eq!(*o.get(), 22);
+ ///
+ /// // We can use the same RustcEntry multiple times.
+ /// *o.get_mut() += 2;
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 24);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_mut(&mut self) -> &mut V {
+ unsafe { &mut self.elem.as_mut().1 }
+ }
+
+ /// Converts the RustcOccupiedEntry into a mutable reference to the value in the entry
+ /// with a lifetime bound to the map itself.
+ ///
+ /// If you need multiple references to the `RustcOccupiedEntry`, see [`get_mut`].
+ ///
+ /// [`get_mut`]: #method.get_mut
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ ///
+ /// assert_eq!(map["poneyland"], 12);
+ /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") {
+ /// *o.into_mut() += 10;
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 22);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_mut(self) -> &'a mut V {
+ unsafe { &mut self.elem.as_mut().1 }
+ }
+
+ /// Sets the value of the entry, and returns the entry's old value.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ ///
+ /// if let RustcEntry::Occupied(mut o) = map.rustc_entry("poneyland") {
+ /// assert_eq!(o.insert(15), 12);
+ /// }
+ ///
+ /// assert_eq!(map["poneyland"], 15);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(&mut self, mut value: V) -> V {
+ let old_value = self.get_mut();
+ mem::swap(&mut value, old_value);
+ value
+ }
+
+ /// Takes the value out of the entry, and returns it.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// map.rustc_entry("poneyland").or_insert(12);
+ ///
+ /// if let RustcEntry::Occupied(o) = map.rustc_entry("poneyland") {
+ /// assert_eq!(o.remove(), 12);
+ /// }
+ ///
+ /// assert_eq!(map.contains_key("poneyland"), false);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove(self) -> V {
+ self.remove_entry().1
+ }
+
+ /// Replaces the entry, returning the old key and value. The new key in the hash map will be
+ /// the key used to create this entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::hash_map::{RustcEntry, HashMap};
+ /// use std::rc::Rc;
+ ///
+ /// let mut map: HashMap<Rc<String>, u32> = HashMap::new();
+ /// map.insert(Rc::new("Stringthing".to_string()), 15);
+ ///
+ /// let my_key = Rc::new("Stringthing".to_string());
+ ///
+ /// if let RustcEntry::Occupied(entry) = map.rustc_entry(my_key) {
+ /// // Also replace the key with a handle to our other key.
+ /// let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16);
+ /// }
+ ///
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace_entry(self, value: V) -> (K, V) {
+ let entry = unsafe { self.elem.as_mut() };
+
+ let old_key = mem::replace(&mut entry.0, self.key.unwrap());
+ let old_value = mem::replace(&mut entry.1, value);
+
+ (old_key, old_value)
+ }
+
+ /// Replaces the key in the hash map with the key used to create this entry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::hash_map::{RustcEntry, HashMap};
+ /// use std::rc::Rc;
+ ///
+ /// let mut map: HashMap<Rc<String>, u32> = HashMap::new();
+ /// let mut known_strings: Vec<Rc<String>> = Vec::new();
+ ///
+ /// // Initialise known strings, run program, etc.
+ ///
+ /// reclaim_memory(&mut map, &known_strings);
+ ///
+ /// fn reclaim_memory(map: &mut HashMap<Rc<String>, u32>, known_strings: &[Rc<String>] ) {
+ /// for s in known_strings {
+ /// if let RustcEntry::Occupied(entry) = map.rustc_entry(s.clone()) {
+ /// // Replaces the entry's key with our version of it in `known_strings`.
+ /// entry.replace_key();
+ /// }
+ /// }
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace_key(self) -> K {
+ let entry = unsafe { self.elem.as_mut() };
+ mem::replace(&mut entry.0, self.key.unwrap())
+ }
+}
+
+impl<'a, K, V> RustcVacantEntry<'a, K, V> {
+ /// Gets a reference to the key that would be used when inserting a value
+ /// through the `RustcVacantEntry`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ /// assert_eq!(map.rustc_entry("poneyland").key(), &"poneyland");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn key(&self) -> &K {
+ &self.key
+ }
+
+ /// Take ownership of the key.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// if let RustcEntry::Vacant(v) = map.rustc_entry("poneyland") {
+ /// v.into_key();
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn into_key(self) -> K {
+ self.key
+ }
+
+ /// Sets the value of the entry with the RustcVacantEntry's key,
+ /// and returns a mutable reference to it.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// if let RustcEntry::Vacant(o) = map.rustc_entry("poneyland") {
+ /// o.insert(37);
+ /// }
+ /// assert_eq!(map["poneyland"], 37);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(self, value: V) -> &'a mut V {
+ let bucket = self.table.insert_no_grow(self.hash, (self.key, value));
+ unsafe { &mut bucket.as_mut().1 }
+ }
+
+ /// Sets the value of the entry with the RustcVacantEntry's key,
+ /// and returns a RustcOccupiedEntry.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashMap;
+ /// use hashbrown::hash_map::RustcEntry;
+ ///
+ /// let mut map: HashMap<&str, u32> = HashMap::new();
+ ///
+ /// if let RustcEntry::Vacant(v) = map.rustc_entry("poneyland") {
+ /// let o = v.insert_entry(37);
+ /// assert_eq!(o.get(), &37);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert_entry(self, value: V) -> RustcOccupiedEntry<'a, K, V> {
+ let bucket = self.table.insert_no_grow(self.hash, (self.key, value));
+ RustcOccupiedEntry {
+ key: None,
+ elem: bucket,
+ table: self.table,
+ }
+ }
+}
+
+impl<K, V> IterMut<'_, K, V> {
+ /// Returns a iterator of references over the remaining items.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn rustc_iter(&self) -> Iter<'_, K, V> {
+ self.iter()
+ }
+}
+
+impl<K, V> IntoIter<K, V> {
+ /// Returns a iterator of references over the remaining items.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn rustc_iter(&self) -> Iter<'_, K, V> {
+ self.iter()
+ }
+}
+
+impl<K, V> Drain<'_, K, V> {
+ /// Returns a iterator of references over the remaining items.
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn rustc_iter(&self) -> Iter<'_, K, V> {
+ self.iter()
+ }
+}
diff --git a/src/scopeguard.rs b/src/scopeguard.rs
new file mode 100644
index 0000000..32c9694
--- /dev/null
+++ b/src/scopeguard.rs
@@ -0,0 +1,49 @@
+// Extracted from the scopeguard crate
+use core::ops::{Deref, DerefMut};
+
+pub struct ScopeGuard<T, F>
+where
+ F: FnMut(&mut T),
+{
+ dropfn: F,
+ value: T,
+}
+
+#[cfg_attr(feature = "inline-more", inline)]
+pub fn guard<T, F>(value: T, dropfn: F) -> ScopeGuard<T, F>
+where
+ F: FnMut(&mut T),
+{
+ ScopeGuard { dropfn, value }
+}
+
+impl<T, F> Deref for ScopeGuard<T, F>
+where
+ F: FnMut(&mut T),
+{
+ type Target = T;
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn deref(&self) -> &T {
+ &self.value
+ }
+}
+
+impl<T, F> DerefMut for ScopeGuard<T, F>
+where
+ F: FnMut(&mut T),
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn deref_mut(&mut self) -> &mut T {
+ &mut self.value
+ }
+}
+
+impl<T, F> Drop for ScopeGuard<T, F>
+where
+ F: FnMut(&mut T),
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ (self.dropfn)(&mut self.value)
+ }
+}
diff --git a/src/set.rs b/src/set.rs
new file mode 100644
index 0000000..b8460fd
--- /dev/null
+++ b/src/set.rs
@@ -0,0 +1,2119 @@
+use crate::TryReserveError;
+use alloc::borrow::ToOwned;
+use core::borrow::Borrow;
+use core::fmt;
+use core::hash::{BuildHasher, Hash};
+use core::iter::{Chain, FromIterator, FusedIterator};
+use core::mem;
+use core::ops::{BitAnd, BitOr, BitXor, Sub};
+
+use super::map::{self, ConsumeAllOnDrop, DefaultHashBuilder, DrainFilterInner, HashMap, Keys};
+
+// Future Optimization (FIXME!)
+// =============================
+//
+// Iteration over zero sized values is a noop. There is no need
+// for `bucket.val` in the case of HashSet. I suppose we would need HKT
+// to get rid of it properly.
+
+/// A hash set implemented as a `HashMap` where the value is `()`.
+///
+/// As with the [`HashMap`] type, a `HashSet` requires that the elements
+/// implement the [`Eq`] and [`Hash`] traits. This can frequently be achieved by
+/// using `#[derive(PartialEq, Eq, Hash)]`. If you implement these yourself,
+/// it is important that the following property holds:
+///
+/// ```text
+/// k1 == k2 -> hash(k1) == hash(k2)
+/// ```
+///
+/// In other words, if two keys are equal, their hashes must be equal.
+///
+///
+/// It is a logic error for an item to be modified in such a way that the
+/// item's hash, as determined by the [`Hash`] trait, or its equality, as
+/// determined by the [`Eq`] trait, changes while it is in the set. This is
+/// normally only possible through [`Cell`], [`RefCell`], global state, I/O, or
+/// unsafe code.
+///
+/// It is also a logic error for the [`Hash`] implementation of a key to panic.
+/// This is generally only possible if the trait is implemented manually. If a
+/// panic does occur then the contents of the `HashSet` may become corrupted and
+/// some items may be dropped from the table.
+///
+/// # Examples
+///
+/// ```
+/// use hashbrown::HashSet;
+/// // Type inference lets us omit an explicit type signature (which
+/// // would be `HashSet<String>` in this example).
+/// let mut books = HashSet::new();
+///
+/// // Add some books.
+/// books.insert("A Dance With Dragons".to_string());
+/// books.insert("To Kill a Mockingbird".to_string());
+/// books.insert("The Odyssey".to_string());
+/// books.insert("The Great Gatsby".to_string());
+///
+/// // Check for a specific one.
+/// if !books.contains("The Winds of Winter") {
+/// println!("We have {} books, but The Winds of Winter ain't one.",
+/// books.len());
+/// }
+///
+/// // Remove a book.
+/// books.remove("The Odyssey");
+///
+/// // Iterate over everything.
+/// for book in &books {
+/// println!("{}", book);
+/// }
+/// ```
+///
+/// The easiest way to use `HashSet` with a custom type is to derive
+/// [`Eq`] and [`Hash`]. We must also derive [`PartialEq`], this will in the
+/// future be implied by [`Eq`].
+///
+/// ```
+/// use hashbrown::HashSet;
+/// #[derive(Hash, Eq, PartialEq, Debug)]
+/// struct Viking {
+/// name: String,
+/// power: usize,
+/// }
+///
+/// let mut vikings = HashSet::new();
+///
+/// vikings.insert(Viking { name: "Einar".to_string(), power: 9 });
+/// vikings.insert(Viking { name: "Einar".to_string(), power: 9 });
+/// vikings.insert(Viking { name: "Olaf".to_string(), power: 4 });
+/// vikings.insert(Viking { name: "Harald".to_string(), power: 8 });
+///
+/// // Use derived implementation to print the vikings.
+/// for x in &vikings {
+/// println!("{:?}", x);
+/// }
+/// ```
+///
+/// A `HashSet` with fixed list of elements can be initialized from an array:
+///
+/// ```
+/// use hashbrown::HashSet;
+///
+/// let viking_names: HashSet<&'static str> =
+/// [ "Einar", "Olaf", "Harald" ].iter().cloned().collect();
+/// // use the values stored in the set
+/// ```
+///
+/// [`Cell`]: https://doc.rust-lang.org/std/cell/struct.Cell.html
+/// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+/// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+/// [`HashMap`]: struct.HashMap.html
+/// [`PartialEq`]: https://doc.rust-lang.org/std/cmp/trait.PartialEq.html
+/// [`RefCell`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html
+pub struct HashSet<T, S = DefaultHashBuilder> {
+ pub(crate) map: HashMap<T, (), S>,
+}
+
+impl<T: Clone, S: Clone> Clone for HashSet<T, S> {
+ fn clone(&self) -> Self {
+ HashSet {
+ map: self.map.clone(),
+ }
+ }
+
+ fn clone_from(&mut self, source: &Self) {
+ self.map.clone_from(&source.map);
+ }
+}
+
+#[cfg(feature = "ahash")]
+impl<T> HashSet<T, DefaultHashBuilder> {
+ /// Creates an empty `HashSet`.
+ ///
+ /// The hash set is initially created with a capacity of 0, so it will not allocate until it
+ /// is first inserted into.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let set: HashSet<i32> = HashSet::new();
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn new() -> Self {
+ Self {
+ map: HashMap::new(),
+ }
+ }
+
+ /// Creates an empty `HashSet` with the specified capacity.
+ ///
+ /// The hash set will be able to hold at least `capacity` elements without
+ /// reallocating. If `capacity` is 0, the hash set will not allocate.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let set: HashSet<i32> = HashSet::with_capacity(10);
+ /// assert!(set.capacity() >= 10);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn with_capacity(capacity: usize) -> Self {
+ Self {
+ map: HashMap::with_capacity(capacity),
+ }
+ }
+}
+
+impl<T, S> HashSet<T, S> {
+ /// Creates a new empty hash set which will use the given hasher to hash
+ /// keys.
+ ///
+ /// The hash set is also created with the default initial capacity.
+ ///
+ /// Warning: `hasher` is normally randomly generated, and
+ /// is designed to allow `HashSet`s to be resistant to attacks that
+ /// cause many collisions and very poor performance. Setting it
+ /// manually using this function can expose a DoS attack vector.
+ ///
+ /// The `hash_builder` passed should implement the [`BuildHasher`] trait for
+ /// the HashMap to be useful, see its documentation for details.
+ ///
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// use hashbrown::hash_map::DefaultHashBuilder;
+ ///
+ /// let s = DefaultHashBuilder::default();
+ /// let mut set = HashSet::with_hasher(s);
+ /// set.insert(2);
+ /// ```
+ ///
+ /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub const fn with_hasher(hasher: S) -> Self {
+ Self {
+ map: HashMap::with_hasher(hasher),
+ }
+ }
+
+ /// Creates an empty `HashSet` with the specified capacity, using
+ /// `hasher` to hash the keys.
+ ///
+ /// The hash set will be able to hold at least `capacity` elements without
+ /// reallocating. If `capacity` is 0, the hash set will not allocate.
+ ///
+ /// Warning: `hasher` is normally randomly generated, and
+ /// is designed to allow `HashSet`s to be resistant to attacks that
+ /// cause many collisions and very poor performance. Setting it
+ /// manually using this function can expose a DoS attack vector.
+ ///
+ /// The `hash_builder` passed should implement the [`BuildHasher`] trait for
+ /// the HashMap to be useful, see its documentation for details.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// use hashbrown::hash_map::DefaultHashBuilder;
+ ///
+ /// let s = DefaultHashBuilder::default();
+ /// let mut set = HashSet::with_capacity_and_hasher(10, s);
+ /// set.insert(1);
+ /// ```
+ ///
+ /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> Self {
+ Self {
+ map: HashMap::with_capacity_and_hasher(capacity, hasher),
+ }
+ }
+
+ /// Returns the number of elements the set can hold without reallocating.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let set: HashSet<i32> = HashSet::with_capacity(100);
+ /// assert!(set.capacity() >= 100);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn capacity(&self) -> usize {
+ self.map.capacity()
+ }
+
+ /// An iterator visiting all elements in arbitrary order.
+ /// The iterator element type is `&'a T`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let mut set = HashSet::new();
+ /// set.insert("a");
+ /// set.insert("b");
+ ///
+ /// // Will print in an arbitrary order.
+ /// for x in set.iter() {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn iter(&self) -> Iter<'_, T> {
+ Iter {
+ iter: self.map.keys(),
+ }
+ }
+
+ /// Returns the number of elements in the set.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut v = HashSet::new();
+ /// assert_eq!(v.len(), 0);
+ /// v.insert(1);
+ /// assert_eq!(v.len(), 1);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn len(&self) -> usize {
+ self.map.len()
+ }
+
+ /// Returns `true` if the set contains no elements.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut v = HashSet::new();
+ /// assert!(v.is_empty());
+ /// v.insert(1);
+ /// assert!(!v.is_empty());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn is_empty(&self) -> bool {
+ self.map.is_empty()
+ }
+
+ /// Clears the set, returning all elements in an iterator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// assert!(!set.is_empty());
+ ///
+ /// // print 1, 2, 3 in an arbitrary order
+ /// for i in set.drain() {
+ /// println!("{}", i);
+ /// }
+ ///
+ /// assert!(set.is_empty());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn drain(&mut self) -> Drain<'_, T> {
+ Drain {
+ iter: self.map.drain(),
+ }
+ }
+
+ /// Retains only the elements specified by the predicate.
+ ///
+ /// In other words, remove all elements `e` such that `f(&e)` returns `false`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let xs = [1,2,3,4,5,6];
+ /// let mut set: HashSet<i32> = xs.iter().cloned().collect();
+ /// set.retain(|&k| k % 2 == 0);
+ /// assert_eq!(set.len(), 3);
+ /// ```
+ pub fn retain<F>(&mut self, mut f: F)
+ where
+ F: FnMut(&T) -> bool,
+ {
+ self.map.retain(|k, _| f(k));
+ }
+
+ /// Drains elements which are true under the given predicate,
+ /// and returns an iterator over the removed items.
+ ///
+ /// In other words, move all elements `e` such that `f(&e)` returns `true` out
+ /// into another iterator.
+ ///
+ /// When the returned DrainedFilter is dropped, any remaining elements that satisfy
+ /// the predicate are dropped from the set.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set: HashSet<i32> = (0..8).collect();
+ /// let drained: HashSet<i32> = set.drain_filter(|v| v % 2 == 0).collect();
+ ///
+ /// let mut evens = drained.into_iter().collect::<Vec<_>>();
+ /// let mut odds = set.into_iter().collect::<Vec<_>>();
+ /// evens.sort();
+ /// odds.sort();
+ ///
+ /// assert_eq!(evens, vec![0, 2, 4, 6]);
+ /// assert_eq!(odds, vec![1, 3, 5, 7]);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn drain_filter<F>(&mut self, f: F) -> DrainFilter<'_, T, F>
+ where
+ F: FnMut(&T) -> bool,
+ {
+ DrainFilter {
+ f,
+ inner: DrainFilterInner {
+ iter: unsafe { self.map.table.iter() },
+ table: &mut self.map.table,
+ },
+ }
+ }
+
+ /// Clears the set, removing all values.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut v = HashSet::new();
+ /// v.insert(1);
+ /// v.clear();
+ /// assert!(v.is_empty());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn clear(&mut self) {
+ self.map.clear()
+ }
+
+ /// Returns a reference to the set's [`BuildHasher`].
+ ///
+ /// [`BuildHasher`]: https://doc.rust-lang.org/std/hash/trait.BuildHasher.html
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// use hashbrown::hash_map::DefaultHashBuilder;
+ ///
+ /// let hasher = DefaultHashBuilder::default();
+ /// let set: HashSet<i32> = HashSet::with_hasher(hasher);
+ /// let hasher: &DefaultHashBuilder = set.hasher();
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn hasher(&self) -> &S {
+ self.map.hasher()
+ }
+}
+
+impl<T, S> HashSet<T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ /// Reserves capacity for at least `additional` more elements to be inserted
+ /// in the `HashSet`. The collection may reserve more space to avoid
+ /// frequent reallocations.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the new allocation size overflows `usize`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let mut set: HashSet<i32> = HashSet::new();
+ /// set.reserve(10);
+ /// assert!(set.capacity() >= 10);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn reserve(&mut self, additional: usize) {
+ self.map.reserve(additional)
+ }
+
+ /// Tries to reserve capacity for at least `additional` more elements to be inserted
+ /// in the given `HashSet<K,V>`. The collection may reserve more space to avoid
+ /// frequent reallocations.
+ ///
+ /// # Errors
+ ///
+ /// If the capacity overflows, or the allocator reports a failure, then an error
+ /// is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let mut set: HashSet<i32> = HashSet::new();
+ /// set.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
+ self.map.try_reserve(additional)
+ }
+
+ /// Shrinks the capacity of the set as much as possible. It will drop
+ /// down as much as possible while maintaining the internal rules
+ /// and possibly leaving some space in accordance with the resize policy.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set = HashSet::with_capacity(100);
+ /// set.insert(1);
+ /// set.insert(2);
+ /// assert!(set.capacity() >= 100);
+ /// set.shrink_to_fit();
+ /// assert!(set.capacity() >= 2);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn shrink_to_fit(&mut self) {
+ self.map.shrink_to_fit()
+ }
+
+ /// Shrinks the capacity of the set with a lower limit. It will drop
+ /// down no lower than the supplied limit while maintaining the internal rules
+ /// and possibly leaving some space in accordance with the resize policy.
+ ///
+ /// Panics if the current capacity is smaller than the supplied
+ /// minimum capacity.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set = HashSet::with_capacity(100);
+ /// set.insert(1);
+ /// set.insert(2);
+ /// assert!(set.capacity() >= 100);
+ /// set.shrink_to(10);
+ /// assert!(set.capacity() >= 10);
+ /// set.shrink_to(0);
+ /// assert!(set.capacity() >= 2);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn shrink_to(&mut self, min_capacity: usize) {
+ self.map.shrink_to(min_capacity)
+ }
+
+ /// Visits the values representing the difference,
+ /// i.e., the values that are in `self` but not in `other`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
+ ///
+ /// // Can be seen as `a - b`.
+ /// for x in a.difference(&b) {
+ /// println!("{}", x); // Print 1
+ /// }
+ ///
+ /// let diff: HashSet<_> = a.difference(&b).collect();
+ /// assert_eq!(diff, [1].iter().collect());
+ ///
+ /// // Note that difference is not symmetric,
+ /// // and `b - a` means something else:
+ /// let diff: HashSet<_> = b.difference(&a).collect();
+ /// assert_eq!(diff, [4].iter().collect());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn difference<'a>(&'a self, other: &'a Self) -> Difference<'a, T, S> {
+ Difference {
+ iter: self.iter(),
+ other,
+ }
+ }
+
+ /// Visits the values representing the symmetric difference,
+ /// i.e., the values that are in `self` or in `other` but not in both.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
+ ///
+ /// // Print 1, 4 in arbitrary order.
+ /// for x in a.symmetric_difference(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// let diff1: HashSet<_> = a.symmetric_difference(&b).collect();
+ /// let diff2: HashSet<_> = b.symmetric_difference(&a).collect();
+ ///
+ /// assert_eq!(diff1, diff2);
+ /// assert_eq!(diff1, [1, 4].iter().collect());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn symmetric_difference<'a>(&'a self, other: &'a Self) -> SymmetricDifference<'a, T, S> {
+ SymmetricDifference {
+ iter: self.difference(other).chain(other.difference(self)),
+ }
+ }
+
+ /// Visits the values representing the intersection,
+ /// i.e., the values that are both in `self` and `other`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
+ ///
+ /// // Print 2, 3 in arbitrary order.
+ /// for x in a.intersection(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// let intersection: HashSet<_> = a.intersection(&b).collect();
+ /// assert_eq!(intersection, [2, 3].iter().collect());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn intersection<'a>(&'a self, other: &'a Self) -> Intersection<'a, T, S> {
+ let (smaller, larger) = if self.len() <= other.len() {
+ (self, other)
+ } else {
+ (other, self)
+ };
+ Intersection {
+ iter: smaller.iter(),
+ other: larger,
+ }
+ }
+
+ /// Visits the values representing the union,
+ /// i.e., all the values in `self` or `other`, without duplicates.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
+ ///
+ /// // Print 1, 2, 3, 4 in arbitrary order.
+ /// for x in a.union(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// let union: HashSet<_> = a.union(&b).collect();
+ /// assert_eq!(union, [1, 2, 3, 4].iter().collect());
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn union<'a>(&'a self, other: &'a Self) -> Union<'a, T, S> {
+ let (smaller, larger) = if self.len() >= other.len() {
+ (self, other)
+ } else {
+ (other, self)
+ };
+ Union {
+ iter: larger.iter().chain(smaller.difference(larger)),
+ }
+ }
+
+ /// Returns `true` if the set contains a value.
+ ///
+ /// The value may be any borrowed form of the set's value type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the value type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// assert_eq!(set.contains(&1), true);
+ /// assert_eq!(set.contains(&4), false);
+ /// ```
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool
+ where
+ T: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.map.contains_key(value)
+ }
+
+ /// Returns a reference to the value in the set, if any, that is equal to the given value.
+ ///
+ /// The value may be any borrowed form of the set's value type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the value type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// assert_eq!(set.get(&2), Some(&2));
+ /// assert_eq!(set.get(&4), None);
+ /// ```
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T>
+ where
+ T: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.map.get_key_value(value) {
+ Some((k, _)) => Some(k),
+ None => None,
+ }
+ }
+
+ /// Inserts the given `value` into the set if it is not present, then
+ /// returns a reference to the value in the set.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// assert_eq!(set.len(), 3);
+ /// assert_eq!(set.get_or_insert(2), &2);
+ /// assert_eq!(set.get_or_insert(100), &100);
+ /// assert_eq!(set.len(), 4); // 100 was inserted
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_or_insert(&mut self, value: T) -> &T {
+ // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with
+ // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`.
+ self.map
+ .raw_entry_mut()
+ .from_key(&value)
+ .or_insert(value, ())
+ .0
+ }
+
+ /// Inserts an owned copy of the given `value` into the set if it is not
+ /// present, then returns a reference to the value in the set.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set: HashSet<String> = ["cat", "dog", "horse"]
+ /// .iter().map(|&pet| pet.to_owned()).collect();
+ ///
+ /// assert_eq!(set.len(), 3);
+ /// for &pet in &["cat", "dog", "fish"] {
+ /// let value = set.get_or_insert_owned(pet);
+ /// assert_eq!(value, pet);
+ /// }
+ /// assert_eq!(set.len(), 4); // a new "fish" was inserted
+ /// ```
+ #[inline]
+ pub fn get_or_insert_owned<Q: ?Sized>(&mut self, value: &Q) -> &T
+ where
+ T: Borrow<Q>,
+ Q: Hash + Eq + ToOwned<Owned = T>,
+ {
+ // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with
+ // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`.
+ self.map
+ .raw_entry_mut()
+ .from_key(value)
+ .or_insert_with(|| (value.to_owned(), ()))
+ .0
+ }
+
+ /// Inserts a value computed from `f` into the set if the given `value` is
+ /// not present, then returns a reference to the value in the set.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set: HashSet<String> = ["cat", "dog", "horse"]
+ /// .iter().map(|&pet| pet.to_owned()).collect();
+ ///
+ /// assert_eq!(set.len(), 3);
+ /// for &pet in &["cat", "dog", "fish"] {
+ /// let value = set.get_or_insert_with(pet, str::to_owned);
+ /// assert_eq!(value, pet);
+ /// }
+ /// assert_eq!(set.len(), 4); // a new "fish" was inserted
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn get_or_insert_with<Q: ?Sized, F>(&mut self, value: &Q, f: F) -> &T
+ where
+ T: Borrow<Q>,
+ Q: Hash + Eq,
+ F: FnOnce(&Q) -> T,
+ {
+ // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with
+ // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`.
+ self.map
+ .raw_entry_mut()
+ .from_key(value)
+ .or_insert_with(|| (f(value), ()))
+ .0
+ }
+
+ /// Returns `true` if `self` has no elements in common with `other`.
+ /// This is equivalent to checking for an empty intersection.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// let mut b = HashSet::new();
+ ///
+ /// assert_eq!(a.is_disjoint(&b), true);
+ /// b.insert(4);
+ /// assert_eq!(a.is_disjoint(&b), true);
+ /// b.insert(1);
+ /// assert_eq!(a.is_disjoint(&b), false);
+ /// ```
+ pub fn is_disjoint(&self, other: &Self) -> bool {
+ self.iter().all(|v| !other.contains(v))
+ }
+
+ /// Returns `true` if the set is a subset of another,
+ /// i.e., `other` contains at least all the values in `self`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// let mut set = HashSet::new();
+ ///
+ /// assert_eq!(set.is_subset(&sup), true);
+ /// set.insert(2);
+ /// assert_eq!(set.is_subset(&sup), true);
+ /// set.insert(4);
+ /// assert_eq!(set.is_subset(&sup), false);
+ /// ```
+ pub fn is_subset(&self, other: &Self) -> bool {
+ self.len() <= other.len() && self.iter().all(|v| other.contains(v))
+ }
+
+ /// Returns `true` if the set is a superset of another,
+ /// i.e., `self` contains at least all the values in `other`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let sub: HashSet<_> = [1, 2].iter().cloned().collect();
+ /// let mut set = HashSet::new();
+ ///
+ /// assert_eq!(set.is_superset(&sub), false);
+ ///
+ /// set.insert(0);
+ /// set.insert(1);
+ /// assert_eq!(set.is_superset(&sub), false);
+ ///
+ /// set.insert(2);
+ /// assert_eq!(set.is_superset(&sub), true);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn is_superset(&self, other: &Self) -> bool {
+ other.is_subset(self)
+ }
+
+ /// Adds a value to the set.
+ ///
+ /// If the set did not have this value present, `true` is returned.
+ ///
+ /// If the set did have this value present, `false` is returned.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set = HashSet::new();
+ ///
+ /// assert_eq!(set.insert(2), true);
+ /// assert_eq!(set.insert(2), false);
+ /// assert_eq!(set.len(), 1);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn insert(&mut self, value: T) -> bool {
+ self.map.insert(value, ()).is_none()
+ }
+
+ /// Adds a value to the set, replacing the existing value, if any, that is equal to the given
+ /// one. Returns the replaced value.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set = HashSet::new();
+ /// set.insert(Vec::<i32>::new());
+ ///
+ /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 0);
+ /// set.replace(Vec::with_capacity(10));
+ /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 10);
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn replace(&mut self, value: T) -> Option<T> {
+ match self.map.entry(value) {
+ map::Entry::Occupied(occupied) => Some(occupied.replace_key()),
+ map::Entry::Vacant(vacant) => {
+ vacant.insert(());
+ None
+ }
+ }
+ }
+
+ /// Removes a value from the set. Returns whether the value was
+ /// present in the set.
+ ///
+ /// The value may be any borrowed form of the set's value type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the value type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set = HashSet::new();
+ ///
+ /// set.insert(2);
+ /// assert_eq!(set.remove(&2), true);
+ /// assert_eq!(set.remove(&2), false);
+ /// ```
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool
+ where
+ T: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ self.map.remove(value).is_some()
+ }
+
+ /// Removes and returns the value in the set, if any, that is equal to the given one.
+ ///
+ /// The value may be any borrowed form of the set's value type, but
+ /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for
+ /// the value type.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect();
+ /// assert_eq!(set.take(&2), Some(2));
+ /// assert_eq!(set.take(&2), None);
+ /// ```
+ ///
+ /// [`Eq`]: https://doc.rust-lang.org/std/cmp/trait.Eq.html
+ /// [`Hash`]: https://doc.rust-lang.org/std/hash/trait.Hash.html
+ #[cfg_attr(feature = "inline-more", inline)]
+ pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
+ where
+ T: Borrow<Q>,
+ Q: Hash + Eq,
+ {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.map.remove_entry(value) {
+ Some((k, _)) => Some(k),
+ None => None,
+ }
+ }
+}
+
+impl<T, S> PartialEq for HashSet<T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ fn eq(&self, other: &Self) -> bool {
+ if self.len() != other.len() {
+ return false;
+ }
+
+ self.iter().all(|key| other.contains(key))
+ }
+}
+
+impl<T, S> Eq for HashSet<T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+}
+
+impl<T, S> fmt::Debug for HashSet<T, S>
+where
+ T: Eq + Hash + fmt::Debug,
+ S: BuildHasher,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_set().entries(self.iter()).finish()
+ }
+}
+
+impl<T, S> FromIterator<T> for HashSet<T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher + Default,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
+ let mut set = Self::with_hasher(Default::default());
+ set.extend(iter);
+ set
+ }
+}
+
+impl<T, S> Extend<T> for HashSet<T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
+ self.map.extend(iter.into_iter().map(|k| (k, ())));
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_one(&mut self, k: T) {
+ self.map.insert(k, ());
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_reserve(&mut self, additional: usize) {
+ Extend::<(T, ())>::extend_reserve(&mut self.map, additional);
+ }
+}
+
+impl<'a, T, S> Extend<&'a T> for HashSet<T, S>
+where
+ T: 'a + Eq + Hash + Copy,
+ S: BuildHasher,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) {
+ self.extend(iter.into_iter().cloned());
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_one(&mut self, k: &'a T) {
+ self.map.insert(*k, ());
+ }
+
+ #[inline]
+ #[cfg(feature = "nightly")]
+ fn extend_reserve(&mut self, additional: usize) {
+ Extend::<(T, ())>::extend_reserve(&mut self.map, additional);
+ }
+}
+
+impl<T, S> Default for HashSet<T, S>
+where
+ S: Default,
+{
+ /// Creates an empty `HashSet<T, S>` with the `Default` value for the hasher.
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn default() -> Self {
+ Self {
+ map: HashMap::default(),
+ }
+ }
+}
+
+impl<T, S> BitOr<&HashSet<T, S>> for &HashSet<T, S>
+where
+ T: Eq + Hash + Clone,
+ S: BuildHasher + Default,
+{
+ type Output = HashSet<T, S>;
+
+ /// Returns the union of `self` and `rhs` as a new `HashSet<T, S>`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect();
+ /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect();
+ ///
+ /// let set = &a | &b;
+ ///
+ /// let mut i = 0;
+ /// let expected = [1, 2, 3, 4, 5];
+ /// for x in &set {
+ /// assert!(expected.contains(x));
+ /// i += 1;
+ /// }
+ /// assert_eq!(i, expected.len());
+ /// ```
+ fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> {
+ self.union(rhs).cloned().collect()
+ }
+}
+
+impl<T, S> BitAnd<&HashSet<T, S>> for &HashSet<T, S>
+where
+ T: Eq + Hash + Clone,
+ S: BuildHasher + Default,
+{
+ type Output = HashSet<T, S>;
+
+ /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, S>`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect();
+ /// let b: HashSet<_> = vec![2, 3, 4].into_iter().collect();
+ ///
+ /// let set = &a & &b;
+ ///
+ /// let mut i = 0;
+ /// let expected = [2, 3];
+ /// for x in &set {
+ /// assert!(expected.contains(x));
+ /// i += 1;
+ /// }
+ /// assert_eq!(i, expected.len());
+ /// ```
+ fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S> {
+ self.intersection(rhs).cloned().collect()
+ }
+}
+
+impl<T, S> BitXor<&HashSet<T, S>> for &HashSet<T, S>
+where
+ T: Eq + Hash + Clone,
+ S: BuildHasher + Default,
+{
+ type Output = HashSet<T, S>;
+
+ /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, S>`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect();
+ /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect();
+ ///
+ /// let set = &a ^ &b;
+ ///
+ /// let mut i = 0;
+ /// let expected = [1, 2, 4, 5];
+ /// for x in &set {
+ /// assert!(expected.contains(x));
+ /// i += 1;
+ /// }
+ /// assert_eq!(i, expected.len());
+ /// ```
+ fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> {
+ self.symmetric_difference(rhs).cloned().collect()
+ }
+}
+
+impl<T, S> Sub<&HashSet<T, S>> for &HashSet<T, S>
+where
+ T: Eq + Hash + Clone,
+ S: BuildHasher + Default,
+{
+ type Output = HashSet<T, S>;
+
+ /// Returns the difference of `self` and `rhs` as a new `HashSet<T, S>`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ ///
+ /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect();
+ /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect();
+ ///
+ /// let set = &a - &b;
+ ///
+ /// let mut i = 0;
+ /// let expected = [1, 2];
+ /// for x in &set {
+ /// assert!(expected.contains(x));
+ /// i += 1;
+ /// }
+ /// assert_eq!(i, expected.len());
+ /// ```
+ fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S> {
+ self.difference(rhs).cloned().collect()
+ }
+}
+
+/// An iterator over the items of a `HashSet`.
+///
+/// This `struct` is created by the [`iter`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`iter`]: struct.HashSet.html#method.iter
+pub struct Iter<'a, K> {
+ iter: Keys<'a, K, ()>,
+}
+
+/// An owning iterator over the items of a `HashSet`.
+///
+/// This `struct` is created by the [`into_iter`] method on [`HashSet`]
+/// (provided by the `IntoIterator` trait). See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`into_iter`]: struct.HashSet.html#method.into_iter
+pub struct IntoIter<K> {
+ iter: map::IntoIter<K, ()>,
+}
+
+/// A draining iterator over the items of a `HashSet`.
+///
+/// This `struct` is created by the [`drain`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`drain`]: struct.HashSet.html#method.drain
+pub struct Drain<'a, K> {
+ iter: map::Drain<'a, K, ()>,
+}
+
+/// A draining iterator over entries of a `HashSet` which don't satisfy the predicate `f`.
+///
+/// This `struct` is created by the [`drain_filter`] method on [`HashSet`]. See its
+/// documentation for more.
+///
+/// [`drain_filter`]: struct.HashSet.html#method.drain_filter
+/// [`HashSet`]: struct.HashSet.html
+pub struct DrainFilter<'a, K, F>
+where
+ F: FnMut(&K) -> bool,
+{
+ f: F,
+ inner: DrainFilterInner<'a, K, ()>,
+}
+
+/// A lazy iterator producing elements in the intersection of `HashSet`s.
+///
+/// This `struct` is created by the [`intersection`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`intersection`]: struct.HashSet.html#method.intersection
+pub struct Intersection<'a, T, S> {
+ // iterator of the first set
+ iter: Iter<'a, T>,
+ // the second set
+ other: &'a HashSet<T, S>,
+}
+
+/// A lazy iterator producing elements in the difference of `HashSet`s.
+///
+/// This `struct` is created by the [`difference`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`difference`]: struct.HashSet.html#method.difference
+pub struct Difference<'a, T, S> {
+ // iterator of the first set
+ iter: Iter<'a, T>,
+ // the second set
+ other: &'a HashSet<T, S>,
+}
+
+/// A lazy iterator producing elements in the symmetric difference of `HashSet`s.
+///
+/// This `struct` is created by the [`symmetric_difference`] method on
+/// [`HashSet`]. See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`symmetric_difference`]: struct.HashSet.html#method.symmetric_difference
+pub struct SymmetricDifference<'a, T, S> {
+ iter: Chain<Difference<'a, T, S>, Difference<'a, T, S>>,
+}
+
+/// A lazy iterator producing elements in the union of `HashSet`s.
+///
+/// This `struct` is created by the [`union`] method on [`HashSet`].
+/// See its documentation for more.
+///
+/// [`HashSet`]: struct.HashSet.html
+/// [`union`]: struct.HashSet.html#method.union
+pub struct Union<'a, T, S> {
+ iter: Chain<Iter<'a, T>, Difference<'a, T, S>>,
+}
+
+impl<'a, T, S> IntoIterator for &'a HashSet<T, S> {
+ type Item = &'a T;
+ type IntoIter = Iter<'a, T>;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_iter(self) -> Iter<'a, T> {
+ self.iter()
+ }
+}
+
+impl<T, S> IntoIterator for HashSet<T, S> {
+ type Item = T;
+ type IntoIter = IntoIter<T>;
+
+ /// Creates a consuming iterator, that is, one that moves each value out
+ /// of the set in arbitrary order. The set cannot be used after calling
+ /// this.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use hashbrown::HashSet;
+ /// let mut set = HashSet::new();
+ /// set.insert("a".to_string());
+ /// set.insert("b".to_string());
+ ///
+ /// // Not possible to collect to a Vec<String> with a regular `.iter()`.
+ /// let v: Vec<String> = set.into_iter().collect();
+ ///
+ /// // Will print in an arbitrary order.
+ /// for x in &v {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn into_iter(self) -> IntoIter<T> {
+ IntoIter {
+ iter: self.map.into_iter(),
+ }
+ }
+}
+
+impl<K> Clone for Iter<'_, K> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Iter {
+ iter: self.iter.clone(),
+ }
+ }
+}
+impl<'a, K> Iterator for Iter<'a, K> {
+ type Item = &'a K;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a K> {
+ self.iter.next()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+impl<'a, K> ExactSizeIterator for Iter<'a, K> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+impl<K> FusedIterator for Iter<'_, K> {}
+
+impl<K: fmt::Debug> fmt::Debug for Iter<'_, K> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+impl<K> Iterator for IntoIter<K> {
+ type Item = K;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<K> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.iter.next() {
+ Some((k, _)) => Some(k),
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+impl<K> ExactSizeIterator for IntoIter<K> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+impl<K> FusedIterator for IntoIter<K> {}
+
+impl<K: fmt::Debug> fmt::Debug for IntoIter<K> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let entries_iter = self.iter.iter().map(|(k, _)| k);
+ f.debug_list().entries(entries_iter).finish()
+ }
+}
+
+impl<K> Iterator for Drain<'_, K> {
+ type Item = K;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<K> {
+ // Avoid `Option::map` because it bloats LLVM IR.
+ match self.iter.next() {
+ Some((k, _)) => Some(k),
+ None => None,
+ }
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+impl<K> ExactSizeIterator for Drain<'_, K> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn len(&self) -> usize {
+ self.iter.len()
+ }
+}
+impl<K> FusedIterator for Drain<'_, K> {}
+
+impl<K: fmt::Debug> fmt::Debug for Drain<'_, K> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ let entries_iter = self.iter.iter().map(|(k, _)| k);
+ f.debug_list().entries(entries_iter).finish()
+ }
+}
+
+impl<'a, K, F> Drop for DrainFilter<'a, K, F>
+where
+ F: FnMut(&K) -> bool,
+{
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn drop(&mut self) {
+ while let Some(item) = self.next() {
+ let guard = ConsumeAllOnDrop(self);
+ drop(item);
+ mem::forget(guard);
+ }
+ }
+}
+
+impl<K, F> Iterator for DrainFilter<'_, K, F>
+where
+ F: FnMut(&K) -> bool,
+{
+ type Item = K;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<Self::Item> {
+ let f = &mut self.f;
+ let (k, _) = self.inner.next(&mut |k, _| f(k))?;
+ Some(k)
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ (0, self.inner.iter.size_hint().1)
+ }
+}
+
+impl<K, F> FusedIterator for DrainFilter<'_, K, F> where F: FnMut(&K) -> bool {}
+
+impl<T, S> Clone for Intersection<'_, T, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Intersection {
+ iter: self.iter.clone(),
+ ..*self
+ }
+ }
+}
+
+impl<'a, T, S> Iterator for Intersection<'a, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ type Item = &'a T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a T> {
+ loop {
+ let elt = self.iter.next()?;
+ if self.other.contains(elt) {
+ return Some(elt);
+ }
+ }
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ let (_, upper) = self.iter.size_hint();
+ (0, upper)
+ }
+}
+
+impl<T, S> fmt::Debug for Intersection<'_, T, S>
+where
+ T: fmt::Debug + Eq + Hash,
+ S: BuildHasher,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+impl<T, S> FusedIterator for Intersection<'_, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+}
+
+impl<T, S> Clone for Difference<'_, T, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Difference {
+ iter: self.iter.clone(),
+ ..*self
+ }
+ }
+}
+
+impl<'a, T, S> Iterator for Difference<'a, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ type Item = &'a T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a T> {
+ loop {
+ let elt = self.iter.next()?;
+ if !self.other.contains(elt) {
+ return Some(elt);
+ }
+ }
+ }
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ let (_, upper) = self.iter.size_hint();
+ (0, upper)
+ }
+}
+
+impl<T, S> FusedIterator for Difference<'_, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+}
+
+impl<T, S> fmt::Debug for Difference<'_, T, S>
+where
+ T: fmt::Debug + Eq + Hash,
+ S: BuildHasher,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+impl<T, S> Clone for SymmetricDifference<'_, T, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ SymmetricDifference {
+ iter: self.iter.clone(),
+ }
+ }
+}
+
+impl<'a, T, S> Iterator for SymmetricDifference<'a, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ type Item = &'a T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a T> {
+ self.iter.next()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+
+impl<T, S> FusedIterator for SymmetricDifference<'_, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+}
+
+impl<T, S> fmt::Debug for SymmetricDifference<'_, T, S>
+where
+ T: fmt::Debug + Eq + Hash,
+ S: BuildHasher,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+impl<T, S> Clone for Union<'_, T, S> {
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn clone(&self) -> Self {
+ Union {
+ iter: self.iter.clone(),
+ }
+ }
+}
+
+impl<T, S> FusedIterator for Union<'_, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+}
+
+impl<T, S> fmt::Debug for Union<'_, T, S>
+where
+ T: fmt::Debug + Eq + Hash,
+ S: BuildHasher,
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.debug_list().entries(self.clone()).finish()
+ }
+}
+
+impl<'a, T, S> Iterator for Union<'a, T, S>
+where
+ T: Eq + Hash,
+ S: BuildHasher,
+{
+ type Item = &'a T;
+
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn next(&mut self) -> Option<&'a T> {
+ self.iter.next()
+ }
+ #[cfg_attr(feature = "inline-more", inline)]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+}
+
+#[allow(dead_code)]
+fn assert_covariance() {
+ fn set<'new>(v: HashSet<&'static str>) -> HashSet<&'new str> {
+ v
+ }
+ fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> {
+ v
+ }
+ fn into_iter<'new>(v: IntoIter<&'static str>) -> IntoIter<&'new str> {
+ v
+ }
+ fn difference<'a, 'new>(
+ v: Difference<'a, &'static str, DefaultHashBuilder>,
+ ) -> Difference<'a, &'new str, DefaultHashBuilder> {
+ v
+ }
+ fn symmetric_difference<'a, 'new>(
+ v: SymmetricDifference<'a, &'static str, DefaultHashBuilder>,
+ ) -> SymmetricDifference<'a, &'new str, DefaultHashBuilder> {
+ v
+ }
+ fn intersection<'a, 'new>(
+ v: Intersection<'a, &'static str, DefaultHashBuilder>,
+ ) -> Intersection<'a, &'new str, DefaultHashBuilder> {
+ v
+ }
+ fn union<'a, 'new>(
+ v: Union<'a, &'static str, DefaultHashBuilder>,
+ ) -> Union<'a, &'new str, DefaultHashBuilder> {
+ v
+ }
+ fn drain<'new>(d: Drain<'static, &'static str>) -> Drain<'new, &'new str> {
+ d
+ }
+}
+
+#[cfg(test)]
+mod test_set {
+ use super::super::map::DefaultHashBuilder;
+ use super::HashSet;
+ use std::vec::Vec;
+
+ #[test]
+ fn test_zero_capacities() {
+ type HS = HashSet<i32>;
+
+ let s = HS::new();
+ assert_eq!(s.capacity(), 0);
+
+ let s = HS::default();
+ assert_eq!(s.capacity(), 0);
+
+ let s = HS::with_hasher(DefaultHashBuilder::default());
+ assert_eq!(s.capacity(), 0);
+
+ let s = HS::with_capacity(0);
+ assert_eq!(s.capacity(), 0);
+
+ let s = HS::with_capacity_and_hasher(0, DefaultHashBuilder::default());
+ assert_eq!(s.capacity(), 0);
+
+ let mut s = HS::new();
+ s.insert(1);
+ s.insert(2);
+ s.remove(&1);
+ s.remove(&2);
+ s.shrink_to_fit();
+ assert_eq!(s.capacity(), 0);
+
+ let mut s = HS::new();
+ s.reserve(0);
+ assert_eq!(s.capacity(), 0);
+ }
+
+ #[test]
+ fn test_disjoint() {
+ let mut xs = HashSet::new();
+ let mut ys = HashSet::new();
+ assert!(xs.is_disjoint(&ys));
+ assert!(ys.is_disjoint(&xs));
+ assert!(xs.insert(5));
+ assert!(ys.insert(11));
+ assert!(xs.is_disjoint(&ys));
+ assert!(ys.is_disjoint(&xs));
+ assert!(xs.insert(7));
+ assert!(xs.insert(19));
+ assert!(xs.insert(4));
+ assert!(ys.insert(2));
+ assert!(ys.insert(-11));
+ assert!(xs.is_disjoint(&ys));
+ assert!(ys.is_disjoint(&xs));
+ assert!(ys.insert(7));
+ assert!(!xs.is_disjoint(&ys));
+ assert!(!ys.is_disjoint(&xs));
+ }
+
+ #[test]
+ fn test_subset_and_superset() {
+ let mut a = HashSet::new();
+ assert!(a.insert(0));
+ assert!(a.insert(5));
+ assert!(a.insert(11));
+ assert!(a.insert(7));
+
+ let mut b = HashSet::new();
+ assert!(b.insert(0));
+ assert!(b.insert(7));
+ assert!(b.insert(19));
+ assert!(b.insert(250));
+ assert!(b.insert(11));
+ assert!(b.insert(200));
+
+ assert!(!a.is_subset(&b));
+ assert!(!a.is_superset(&b));
+ assert!(!b.is_subset(&a));
+ assert!(!b.is_superset(&a));
+
+ assert!(b.insert(5));
+
+ assert!(a.is_subset(&b));
+ assert!(!a.is_superset(&b));
+ assert!(!b.is_subset(&a));
+ assert!(b.is_superset(&a));
+ }
+
+ #[test]
+ fn test_iterate() {
+ let mut a = HashSet::new();
+ for i in 0..32 {
+ assert!(a.insert(i));
+ }
+ let mut observed: u32 = 0;
+ for k in &a {
+ observed |= 1 << *k;
+ }
+ assert_eq!(observed, 0xFFFF_FFFF);
+ }
+
+ #[test]
+ fn test_intersection() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(11));
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(77));
+ assert!(a.insert(103));
+ assert!(a.insert(5));
+ assert!(a.insert(-5));
+
+ assert!(b.insert(2));
+ assert!(b.insert(11));
+ assert!(b.insert(77));
+ assert!(b.insert(-9));
+ assert!(b.insert(-42));
+ assert!(b.insert(5));
+ assert!(b.insert(3));
+
+ let mut i = 0;
+ let expected = [3, 5, 11, 77];
+ for x in a.intersection(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_difference() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(3));
+ assert!(b.insert(9));
+
+ let mut i = 0;
+ let expected = [1, 5, 11];
+ for x in a.difference(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_symmetric_difference() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(-2));
+ assert!(b.insert(3));
+ assert!(b.insert(9));
+ assert!(b.insert(14));
+ assert!(b.insert(22));
+
+ let mut i = 0;
+ let expected = [-2, 1, 5, 11, 14, 22];
+ for x in a.symmetric_difference(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_union() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+ assert!(a.insert(16));
+ assert!(a.insert(19));
+ assert!(a.insert(24));
+
+ assert!(b.insert(-2));
+ assert!(b.insert(1));
+ assert!(b.insert(5));
+ assert!(b.insert(9));
+ assert!(b.insert(13));
+ assert!(b.insert(19));
+
+ let mut i = 0;
+ let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
+ for x in a.union(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_from_iter() {
+ let xs = [1, 2, 2, 3, 4, 5, 6, 7, 8, 9];
+
+ let set: HashSet<_> = xs.iter().cloned().collect();
+
+ for x in &xs {
+ assert!(set.contains(x));
+ }
+
+ assert_eq!(set.iter().len(), xs.len() - 1);
+ }
+
+ #[test]
+ fn test_move_iter() {
+ let hs = {
+ let mut hs = HashSet::new();
+
+ hs.insert('a');
+ hs.insert('b');
+
+ hs
+ };
+
+ let v = hs.into_iter().collect::<Vec<char>>();
+ assert!(v == ['a', 'b'] || v == ['b', 'a']);
+ }
+
+ #[test]
+ fn test_eq() {
+ // These constants once happened to expose a bug in insert().
+ // I'm keeping them around to prevent a regression.
+ let mut s1 = HashSet::new();
+
+ s1.insert(1);
+ s1.insert(2);
+ s1.insert(3);
+
+ let mut s2 = HashSet::new();
+
+ s2.insert(1);
+ s2.insert(2);
+
+ assert!(s1 != s2);
+
+ s2.insert(3);
+
+ assert_eq!(s1, s2);
+ }
+
+ #[test]
+ fn test_show() {
+ let mut set = HashSet::new();
+ let empty = HashSet::<i32>::new();
+
+ set.insert(1);
+ set.insert(2);
+
+ let set_str = format!("{:?}", set);
+
+ assert!(set_str == "{1, 2}" || set_str == "{2, 1}");
+ assert_eq!(format!("{:?}", empty), "{}");
+ }
+
+ #[test]
+ fn test_trivial_drain() {
+ let mut s = HashSet::<i32>::new();
+ for _ in s.drain() {}
+ assert!(s.is_empty());
+ drop(s);
+
+ let mut s = HashSet::<i32>::new();
+ drop(s.drain());
+ assert!(s.is_empty());
+ }
+
+ #[test]
+ fn test_drain() {
+ let mut s: HashSet<_> = (1..100).collect();
+
+ // try this a bunch of times to make sure we don't screw up internal state.
+ for _ in 0..20 {
+ assert_eq!(s.len(), 99);
+
+ {
+ let mut last_i = 0;
+ let mut d = s.drain();
+ for (i, x) in d.by_ref().take(50).enumerate() {
+ last_i = i;
+ assert!(x != 0);
+ }
+ assert_eq!(last_i, 49);
+ }
+
+ for _ in &s {
+ panic!("s should be empty!");
+ }
+
+ // reset to try again.
+ s.extend(1..100);
+ }
+ }
+
+ #[test]
+ fn test_replace() {
+ use core::hash;
+
+ #[derive(Debug)]
+ struct Foo(&'static str, i32);
+
+ impl PartialEq for Foo {
+ fn eq(&self, other: &Self) -> bool {
+ self.0 == other.0
+ }
+ }
+
+ impl Eq for Foo {}
+
+ impl hash::Hash for Foo {
+ fn hash<H: hash::Hasher>(&self, h: &mut H) {
+ self.0.hash(h);
+ }
+ }
+
+ let mut s = HashSet::new();
+ assert_eq!(s.replace(Foo("a", 1)), None);
+ assert_eq!(s.len(), 1);
+ assert_eq!(s.replace(Foo("a", 2)), Some(Foo("a", 1)));
+ assert_eq!(s.len(), 1);
+
+ let mut it = s.iter();
+ assert_eq!(it.next(), Some(&Foo("a", 2)));
+ assert_eq!(it.next(), None);
+ }
+
+ #[test]
+ fn test_extend_ref() {
+ let mut a = HashSet::new();
+ a.insert(1);
+
+ a.extend(&[2, 3, 4]);
+
+ assert_eq!(a.len(), 4);
+ assert!(a.contains(&1));
+ assert!(a.contains(&2));
+ assert!(a.contains(&3));
+ assert!(a.contains(&4));
+
+ let mut b = HashSet::new();
+ b.insert(5);
+ b.insert(6);
+
+ a.extend(&b);
+
+ assert_eq!(a.len(), 6);
+ assert!(a.contains(&1));
+ assert!(a.contains(&2));
+ assert!(a.contains(&3));
+ assert!(a.contains(&4));
+ assert!(a.contains(&5));
+ assert!(a.contains(&6));
+ }
+
+ #[test]
+ fn test_retain() {
+ let xs = [1, 2, 3, 4, 5, 6];
+ let mut set: HashSet<i32> = xs.iter().cloned().collect();
+ set.retain(|&k| k % 2 == 0);
+ assert_eq!(set.len(), 3);
+ assert!(set.contains(&2));
+ assert!(set.contains(&4));
+ assert!(set.contains(&6));
+ }
+
+ #[test]
+ fn test_drain_filter() {
+ {
+ let mut set: HashSet<i32> = (0..8).collect();
+ let drained = set.drain_filter(|&k| k % 2 == 0);
+ let mut out = drained.collect::<Vec<_>>();
+ out.sort_unstable();
+ assert_eq!(vec![0, 2, 4, 6], out);
+ assert_eq!(set.len(), 4);
+ }
+ {
+ let mut set: HashSet<i32> = (0..8).collect();
+ drop(set.drain_filter(|&k| k % 2 == 0));
+ assert_eq!(set.len(), 4, "Removes non-matching items on drop");
+ }
+ }
+
+ #[test]
+ fn test_const_with_hasher() {
+ use core::hash::BuildHasher;
+ use std::collections::hash_map::DefaultHasher;
+
+ #[derive(Clone)]
+ struct MyHasher;
+ impl BuildHasher for MyHasher {
+ type Hasher = DefaultHasher;
+
+ fn build_hasher(&self) -> DefaultHasher {
+ DefaultHasher::new()
+ }
+ }
+
+ const EMPTY_SET: HashSet<u32, MyHasher> = HashSet::with_hasher(MyHasher);
+
+ let mut set = EMPTY_SET.clone();
+ set.insert(19);
+ assert!(set.contains(&19));
+ }
+}
diff --git a/tests/hasher.rs b/tests/hasher.rs
new file mode 100644
index 0000000..e455e3d
--- /dev/null
+++ b/tests/hasher.rs
@@ -0,0 +1,65 @@
+//! Sanity check that alternate hashers work correctly.
+
+#![cfg(not(miri))] // FIXME: takes too long
+
+use hashbrown::HashSet;
+use std::hash::{BuildHasher, BuildHasherDefault, Hasher};
+
+fn check<S: BuildHasher + Default>() {
+ let range = 0..1_000;
+
+ let mut set = HashSet::<i32, S>::default();
+ set.extend(range.clone());
+
+ assert!(!set.contains(&i32::min_value()));
+ assert!(!set.contains(&(range.start - 1)));
+ for i in range.clone() {
+ assert!(set.contains(&i));
+ }
+ assert!(!set.contains(&range.end));
+ assert!(!set.contains(&i32::max_value()));
+}
+
+/// Use hashbrown's default hasher.
+#[test]
+fn default() {
+ check::<hashbrown::hash_map::DefaultHashBuilder>();
+}
+
+/// Use std's default hasher.
+#[test]
+fn random_state() {
+ check::<std::collections::hash_map::RandomState>();
+}
+
+/// Use a constant 0 hash.
+#[test]
+fn zero() {
+ #[derive(Default)]
+ struct ZeroHasher;
+
+ impl Hasher for ZeroHasher {
+ fn finish(&self) -> u64 {
+ 0
+ }
+ fn write(&mut self, _: &[u8]) {}
+ }
+
+ check::<BuildHasherDefault<ZeroHasher>>();
+}
+
+/// Use a constant maximum hash.
+#[test]
+fn max() {
+ #[derive(Default)]
+ struct MaxHasher;
+
+ impl Hasher for MaxHasher {
+ fn finish(&self) -> u64 {
+ u64::max_value()
+ }
+ fn write(&mut self, _: &[u8]) {}
+ }
+
+ check::<BuildHasherDefault<MaxHasher>>();
+}
diff --git a/tests/rayon.rs b/tests/rayon.rs
new file mode 100644
index 0000000..39b4770
--- /dev/null
+++ b/tests/rayon.rs
@@ -0,0 +1,533 @@
+#![cfg(feature = "rayon")]
+
+#[macro_use]
+extern crate lazy_static;
+
+use hashbrown::{HashMap, HashSet};
+use rayon::iter::{
+ IntoParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, ParallelExtend,
+ ParallelIterator,
+};
+
+macro_rules! assert_eq3 {
+ ($e1:expr, $e2:expr, $e3:expr) => {{
+ assert_eq!($e1, $e2);
+ assert_eq!($e1, $e3);
+ assert_eq!($e2, $e3);
+ }};
+}
+
+lazy_static! {
+ static ref MAP_EMPTY: HashMap<char, u32> = HashMap::new();
+ static ref MAP: HashMap<char, u32> = {
+ let mut m = HashMap::new();
+ m.insert('b', 20);
+ m.insert('a', 10);
+ m.insert('c', 30);
+ m.insert('e', 50);
+ m.insert('f', 60);
+ m.insert('d', 40);
+ m
+ };
+}
+
+#[test]
+fn map_seq_par_equivalence_iter_empty() {
+ let vec_seq = MAP_EMPTY.iter().collect::<Vec<_>>();
+ let vec_par = MAP_EMPTY.par_iter().collect::<Vec<_>>();
+
+ assert_eq3!(vec_seq, vec_par, []);
+}
+
+#[test]
+fn map_seq_par_equivalence_iter() {
+ let mut vec_seq = MAP.iter().collect::<Vec<_>>();
+ let mut vec_par = MAP.par_iter().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [
+ (&'a', &10),
+ (&'b', &20),
+ (&'c', &30),
+ (&'d', &40),
+ (&'e', &50),
+ (&'f', &60),
+ ];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+#[test]
+fn map_seq_par_equivalence_keys_empty() {
+ let vec_seq = MAP_EMPTY.keys().collect::<Vec<&char>>();
+ let vec_par = MAP_EMPTY.par_keys().collect::<Vec<&char>>();
+
+ let expected: [&char; 0] = [];
+
+ assert_eq3!(vec_seq, vec_par, expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_keys() {
+ let mut vec_seq = MAP.keys().collect::<Vec<_>>();
+ let mut vec_par = MAP.par_keys().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [&'a', &'b', &'c', &'d', &'e', &'f'];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+#[test]
+fn map_seq_par_equivalence_values_empty() {
+ let vec_seq = MAP_EMPTY.values().collect::<Vec<_>>();
+ let vec_par = MAP_EMPTY.par_values().collect::<Vec<_>>();
+
+ let expected: [&u32; 0] = [];
+
+ assert_eq3!(vec_seq, vec_par, expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_values() {
+ let mut vec_seq = MAP.values().collect::<Vec<_>>();
+ let mut vec_par = MAP.par_values().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [&10, &20, &30, &40, &50, &60];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+#[test]
+fn map_seq_par_equivalence_iter_mut_empty() {
+ let mut map1 = MAP_EMPTY.clone();
+ let mut map2 = MAP_EMPTY.clone();
+
+ let vec_seq = map1.iter_mut().collect::<Vec<_>>();
+ let vec_par = map2.par_iter_mut().collect::<Vec<_>>();
+
+ assert_eq3!(vec_seq, vec_par, []);
+}
+
+#[test]
+fn map_seq_par_equivalence_iter_mut() {
+ let mut map1 = MAP.clone();
+ let mut map2 = MAP.clone();
+
+ let mut vec_seq = map1.iter_mut().collect::<Vec<_>>();
+ let mut vec_par = map2.par_iter_mut().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [
+ (&'a', &mut 10),
+ (&'b', &mut 20),
+ (&'c', &mut 30),
+ (&'d', &mut 40),
+ (&'e', &mut 50),
+ (&'f', &mut 60),
+ ];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+#[test]
+fn map_seq_par_equivalence_values_mut_empty() {
+ let mut map1 = MAP_EMPTY.clone();
+ let mut map2 = MAP_EMPTY.clone();
+
+ let vec_seq = map1.values_mut().collect::<Vec<_>>();
+ let vec_par = map2.par_values_mut().collect::<Vec<_>>();
+
+ let expected: [&u32; 0] = [];
+
+ assert_eq3!(vec_seq, vec_par, expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_values_mut() {
+ let mut map1 = MAP.clone();
+ let mut map2 = MAP.clone();
+
+ let mut vec_seq = map1.values_mut().collect::<Vec<_>>();
+ let mut vec_par = map2.par_values_mut().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [&mut 10, &mut 20, &mut 30, &mut 40, &mut 50, &mut 60];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+#[test]
+fn map_seq_par_equivalence_into_iter_empty() {
+ let vec_seq = MAP_EMPTY.clone().into_iter().collect::<Vec<_>>();
+ let vec_par = MAP_EMPTY.clone().into_par_iter().collect::<Vec<_>>();
+
+ assert_eq3!(vec_seq, vec_par, []);
+}
+
+#[test]
+fn map_seq_par_equivalence_into_iter() {
+ let mut vec_seq = MAP.clone().into_iter().collect::<Vec<_>>();
+ let mut vec_par = MAP.clone().into_par_iter().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [
+ ('a', 10),
+ ('b', 20),
+ ('c', 30),
+ ('d', 40),
+ ('e', 50),
+ ('f', 60),
+ ];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+lazy_static! {
+ static ref MAP_VEC_EMPTY: Vec<(char, u32)> = vec![];
+ static ref MAP_VEC: Vec<(char, u32)> = vec![
+ ('b', 20),
+ ('a', 10),
+ ('c', 30),
+ ('e', 50),
+ ('f', 60),
+ ('d', 40),
+ ];
+}
+
+#[test]
+fn map_seq_par_equivalence_collect_empty() {
+ let map_expected = MAP_EMPTY.clone();
+ let map_seq = MAP_VEC_EMPTY.clone().into_iter().collect::<HashMap<_, _>>();
+ let map_par = MAP_VEC_EMPTY
+ .clone()
+ .into_par_iter()
+ .collect::<HashMap<_, _>>();
+
+ assert_eq!(map_seq, map_par);
+ assert_eq!(map_seq, map_expected);
+ assert_eq!(map_par, map_expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_collect() {
+ let map_expected = MAP.clone();
+ let map_seq = MAP_VEC.clone().into_iter().collect::<HashMap<_, _>>();
+ let map_par = MAP_VEC.clone().into_par_iter().collect::<HashMap<_, _>>();
+
+ assert_eq!(map_seq, map_par);
+ assert_eq!(map_seq, map_expected);
+ assert_eq!(map_par, map_expected);
+}
+
+lazy_static! {
+ static ref MAP_EXISTING_EMPTY: HashMap<char, u32> = HashMap::new();
+ static ref MAP_EXISTING: HashMap<char, u32> = {
+ let mut m = HashMap::new();
+ m.insert('b', 20);
+ m.insert('a', 10);
+ m
+ };
+ static ref MAP_EXTENSION_EMPTY: Vec<(char, u32)> = vec![];
+ static ref MAP_EXTENSION: Vec<(char, u32)> = vec![('c', 30), ('e', 50), ('f', 60), ('d', 40),];
+}
+
+#[test]
+fn map_seq_par_equivalence_existing_empty_extend_empty() {
+ let expected = HashMap::new();
+ let mut map_seq = MAP_EXISTING_EMPTY.clone();
+ let mut map_par = MAP_EXISTING_EMPTY.clone();
+
+ map_seq.extend(MAP_EXTENSION_EMPTY.iter().cloned());
+ map_par.par_extend(MAP_EXTENSION_EMPTY.par_iter().cloned());
+
+ assert_eq3!(map_seq, map_par, expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_existing_empty_extend() {
+ let expected = MAP_EXTENSION.iter().cloned().collect::<HashMap<_, _>>();
+ let mut map_seq = MAP_EXISTING_EMPTY.clone();
+ let mut map_par = MAP_EXISTING_EMPTY.clone();
+
+ map_seq.extend(MAP_EXTENSION.iter().cloned());
+ map_par.par_extend(MAP_EXTENSION.par_iter().cloned());
+
+ assert_eq3!(map_seq, map_par, expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_existing_extend_empty() {
+ let expected = MAP_EXISTING.clone();
+ let mut map_seq = MAP_EXISTING.clone();
+ let mut map_par = MAP_EXISTING.clone();
+
+ map_seq.extend(MAP_EXTENSION_EMPTY.iter().cloned());
+ map_par.par_extend(MAP_EXTENSION_EMPTY.par_iter().cloned());
+
+ assert_eq3!(map_seq, map_par, expected);
+}
+
+#[test]
+fn map_seq_par_equivalence_existing_extend() {
+ let expected = MAP.clone();
+ let mut map_seq = MAP_EXISTING.clone();
+ let mut map_par = MAP_EXISTING.clone();
+
+ map_seq.extend(MAP_EXTENSION.iter().cloned());
+ map_par.par_extend(MAP_EXTENSION.par_iter().cloned());
+
+ assert_eq3!(map_seq, map_par, expected);
+}
+
+lazy_static! {
+ static ref SET_EMPTY: HashSet<char> = HashSet::new();
+ static ref SET: HashSet<char> = {
+ let mut s = HashSet::new();
+ s.insert('b');
+ s.insert('a');
+ s.insert('c');
+ s.insert('e');
+ s.insert('f');
+ s.insert('d');
+ s
+ };
+}
+
+#[test]
+fn set_seq_par_equivalence_iter_empty() {
+ let vec_seq = SET_EMPTY.iter().collect::<Vec<_>>();
+ let vec_par = SET_EMPTY.par_iter().collect::<Vec<_>>();
+
+ let expected: [&char; 0] = [];
+
+ assert_eq3!(vec_seq, vec_par, expected);
+}
+
+#[test]
+fn set_seq_par_equivalence_iter() {
+ let mut vec_seq = SET.iter().collect::<Vec<_>>();
+ let mut vec_par = SET.par_iter().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = [&'a', &'b', &'c', &'d', &'e', &'f'];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+#[test]
+fn set_seq_par_equivalence_into_iter_empty() {
+ let vec_seq = SET_EMPTY.clone().into_iter().collect::<Vec<_>>();
+ let vec_par = SET_EMPTY.clone().into_par_iter().collect::<Vec<_>>();
+
+ assert_eq3!(vec_seq, vec_par, []);
+}
+
+#[test]
+fn set_seq_par_equivalence_into_iter() {
+ let mut vec_seq = SET.clone().into_iter().collect::<Vec<_>>();
+ let mut vec_par = SET.clone().into_par_iter().collect::<Vec<_>>();
+
+ assert_eq!(vec_seq, vec_par);
+
+ // Do not depend on the exact order of values
+ let expected_sorted = ['a', 'b', 'c', 'd', 'e', 'f'];
+
+ vec_seq.sort_unstable();
+ vec_par.sort_unstable();
+
+ assert_eq3!(vec_seq, vec_par, expected_sorted);
+}
+
+lazy_static! {
+ static ref SET_VEC_EMPTY: Vec<char> = vec![];
+ static ref SET_VEC: Vec<char> = vec!['b', 'a', 'c', 'e', 'f', 'd',];
+}
+
+#[test]
+fn set_seq_par_equivalence_collect_empty() {
+ let set_expected = SET_EMPTY.clone();
+ let set_seq = SET_VEC_EMPTY.clone().into_iter().collect::<HashSet<_>>();
+ let set_par = SET_VEC_EMPTY
+ .clone()
+ .into_par_iter()
+ .collect::<HashSet<_>>();
+
+ assert_eq!(set_seq, set_par);
+ assert_eq!(set_seq, set_expected);
+ assert_eq!(set_par, set_expected);
+}
+
+#[test]
+fn set_seq_par_equivalence_collect() {
+ let set_expected = SET.clone();
+ let set_seq = SET_VEC.clone().into_iter().collect::<HashSet<_>>();
+ let set_par = SET_VEC.clone().into_par_iter().collect::<HashSet<_>>();
+
+ assert_eq!(set_seq, set_par);
+ assert_eq!(set_seq, set_expected);
+ assert_eq!(set_par, set_expected);
+}
+
+lazy_static! {
+ static ref SET_EXISTING_EMPTY: HashSet<char> = HashSet::new();
+ static ref SET_EXISTING: HashSet<char> = {
+ let mut s = HashSet::new();
+ s.insert('b');
+ s.insert('a');
+ s
+ };
+ static ref SET_EXTENSION_EMPTY: Vec<char> = vec![];
+ static ref SET_EXTENSION: Vec<char> = vec!['c', 'e', 'f', 'd',];
+}
+
+#[test]
+fn set_seq_par_equivalence_existing_empty_extend_empty() {
+ let expected = HashSet::new();
+ let mut set_seq = SET_EXISTING_EMPTY.clone();
+ let mut set_par = SET_EXISTING_EMPTY.clone();
+
+ set_seq.extend(SET_EXTENSION_EMPTY.iter().cloned());
+ set_par.par_extend(SET_EXTENSION_EMPTY.par_iter().cloned());
+
+ assert_eq3!(set_seq, set_par, expected);
+}
+
+#[test]
+fn set_seq_par_equivalence_existing_empty_extend() {
+ let expected = SET_EXTENSION.iter().cloned().collect::<HashSet<_>>();
+ let mut set_seq = SET_EXISTING_EMPTY.clone();
+ let mut set_par = SET_EXISTING_EMPTY.clone();
+
+ set_seq.extend(SET_EXTENSION.iter().cloned());
+ set_par.par_extend(SET_EXTENSION.par_iter().cloned());
+
+ assert_eq3!(set_seq, set_par, expected);
+}
+
+#[test]
+fn set_seq_par_equivalence_existing_extend_empty() {
+ let expected = SET_EXISTING.clone();
+ let mut set_seq = SET_EXISTING.clone();
+ let mut set_par = SET_EXISTING.clone();
+
+ set_seq.extend(SET_EXTENSION_EMPTY.iter().cloned());
+ set_par.par_extend(SET_EXTENSION_EMPTY.par_iter().cloned());
+
+ assert_eq3!(set_seq, set_par, expected);
+}
+
+#[test]
+fn set_seq_par_equivalence_existing_extend() {
+ let expected = SET.clone();
+ let mut set_seq = SET_EXISTING.clone();
+ let mut set_par = SET_EXISTING.clone();
+
+ set_seq.extend(SET_EXTENSION.iter().cloned());
+ set_par.par_extend(SET_EXTENSION.par_iter().cloned());
+
+ assert_eq3!(set_seq, set_par, expected);
+}
+
+lazy_static! {
+ static ref SET_A: HashSet<char> = ['a', 'b', 'c', 'd'].iter().cloned().collect();
+ static ref SET_B: HashSet<char> = ['a', 'b', 'e', 'f'].iter().cloned().collect();
+ static ref SET_DIFF_AB: HashSet<char> = ['c', 'd'].iter().cloned().collect();
+ static ref SET_DIFF_BA: HashSet<char> = ['e', 'f'].iter().cloned().collect();
+ static ref SET_SYMM_DIFF_AB: HashSet<char> = ['c', 'd', 'e', 'f'].iter().cloned().collect();
+ static ref SET_INTERSECTION_AB: HashSet<char> = ['a', 'b'].iter().cloned().collect();
+ static ref SET_UNION_AB: HashSet<char> =
+ ['a', 'b', 'c', 'd', 'e', 'f'].iter().cloned().collect();
+}
+
+#[test]
+fn set_seq_par_equivalence_difference() {
+ let diff_ab_seq = SET_A.difference(&*SET_B).cloned().collect::<HashSet<_>>();
+ let diff_ab_par = SET_A
+ .par_difference(&*SET_B)
+ .cloned()
+ .collect::<HashSet<_>>();
+
+ assert_eq3!(diff_ab_seq, diff_ab_par, *SET_DIFF_AB);
+
+ let diff_ba_seq = SET_B.difference(&*SET_A).cloned().collect::<HashSet<_>>();
+ let diff_ba_par = SET_B
+ .par_difference(&*SET_A)
+ .cloned()
+ .collect::<HashSet<_>>();
+
+ assert_eq3!(diff_ba_seq, diff_ba_par, *SET_DIFF_BA);
+}
+
+#[test]
+fn set_seq_par_equivalence_symmetric_difference() {
+ let symm_diff_ab_seq = SET_A
+ .symmetric_difference(&*SET_B)
+ .cloned()
+ .collect::<HashSet<_>>();
+ let symm_diff_ab_par = SET_A
+ .par_symmetric_difference(&*SET_B)
+ .cloned()
+ .collect::<HashSet<_>>();
+
+ assert_eq3!(symm_diff_ab_seq, symm_diff_ab_par, *SET_SYMM_DIFF_AB);
+}
+
+#[test]
+fn set_seq_par_equivalence_intersection() {
+ let intersection_ab_seq = SET_A.intersection(&*SET_B).cloned().collect::<HashSet<_>>();
+ let intersection_ab_par = SET_A
+ .par_intersection(&*SET_B)
+ .cloned()
+ .collect::<HashSet<_>>();
+
+ assert_eq3!(
+ intersection_ab_seq,
+ intersection_ab_par,
+ *SET_INTERSECTION_AB
+ );
+}
+
+#[test]
+fn set_seq_par_equivalence_union() {
+ let union_ab_seq = SET_A.union(&*SET_B).cloned().collect::<HashSet<_>>();
+ let union_ab_par = SET_A.par_union(&*SET_B).cloned().collect::<HashSet<_>>();
+
+ assert_eq3!(union_ab_seq, union_ab_par, *SET_UNION_AB);
+}
diff --git a/tests/serde.rs b/tests/serde.rs
new file mode 100644
index 0000000..570bf70
--- /dev/null
+++ b/tests/serde.rs
@@ -0,0 +1,65 @@
+#![cfg(feature = "serde")]
+
+use core::hash::BuildHasherDefault;
+use hashbrown::{HashMap, HashSet};
+use rustc_hash::FxHasher;
+use serde_test::{assert_tokens, Token};
+
+// We use FxHash for this test because we rely on the ordering
+type FxHashMap<K, V> = HashMap<K, V, BuildHasherDefault<FxHasher>>;
+type FxHashSet<T> = HashSet<T, BuildHasherDefault<FxHasher>>;
+
+#[test]
+fn map_serde_tokens_empty() {
+ let map = FxHashMap::<char, u32>::default();
+
+ assert_tokens(&map, &[Token::Map { len: Some(0) }, Token::MapEnd]);
+}
+
+#[test]
+fn map_serde_tokens() {
+ let mut map = FxHashMap::default();
+ map.insert('b', 20);
+ map.insert('a', 10);
+ map.insert('c', 30);
+
+ assert_tokens(
+ &map,
+ &[
+ Token::Map { len: Some(3) },
+ Token::Char('a'),
+ Token::I32(10),
+ Token::Char('b'),
+ Token::I32(20),
+ Token::Char('c'),
+ Token::I32(30),
+ Token::MapEnd,
+ ],
+ );
+}
+
+#[test]
+fn set_serde_tokens_empty() {
+ let set = FxHashSet::<u32>::default();
+
+ assert_tokens(&set, &[Token::Seq { len: Some(0) }, Token::SeqEnd]);
+}
+
+#[test]
+fn set_serde_tokens() {
+ let mut set = FxHashSet::default();
+ set.insert(20);
+ set.insert(10);
+ set.insert(30);
+
+ assert_tokens(
+ &set,
+ &[
+ Token::Seq { len: Some(3) },
+ Token::I32(20),
+ Token::I32(10),
+ Token::I32(30),
+ Token::SeqEnd,
+ ],
+ );
+}
diff --git a/tests/set.rs b/tests/set.rs
new file mode 100644
index 0000000..3fc0717
--- /dev/null
+++ b/tests/set.rs
@@ -0,0 +1,30 @@
+#![cfg(not(miri))] // FIXME: takes too long
+
+use hashbrown::HashSet;
+use rand::{distributions::Alphanumeric, rngs::SmallRng, Rng, SeedableRng};
+
+#[test]
+fn test_hashset_insert_remove() {
+ let mut m: HashSet<Vec<char>> = HashSet::new();
+ //let num: u32 = 4096;
+ //let tx: Vec<Vec<u8>> = (0..num).map(|i| (i..(16 + i)).collect()).collect();
+ let seed: [u8; 16] = [
+ 130, 220, 246, 217, 111, 124, 221, 189, 190, 234, 121, 93, 67, 95, 100, 43,
+ ];
+
+ let rng = &mut SmallRng::from_seed(seed);
+ let tx: Vec<Vec<char>> = (0..4096)
+ .map(|_| (rng.sample_iter(&Alphanumeric).take(32).collect()))
+ .collect();
+
+ for _ in 0..32 {
+ for i in 0..4096 {
+ assert_eq!(m.contains(&tx[i].clone()), false);
+ assert_eq!(m.insert(tx[i].clone()), true);
+ }
+ for i in 0..4096 {
+ println!("removing {} {:?}", i, tx[i]);
+ assert_eq!(m.remove(&tx[i]), true);
+ }
+ }
+}
