| //! [![github]](https://github.com/dtolnay/semver) [![crates-io]](https://crates.io/crates/semver) [![docs-rs]](https://docs.rs/semver) | 
 | //! | 
 | //! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github | 
 | //! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust | 
 | //! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs | 
 | //! | 
 | //! <br> | 
 | //! | 
 | //! A parser and evaluator for Cargo's flavor of Semantic Versioning. | 
 | //! | 
 | //! Semantic Versioning (see <https://semver.org>) is a guideline for how | 
 | //! version numbers are assigned and incremented. It is widely followed within | 
 | //! the Cargo/crates.io ecosystem for Rust. | 
 | //! | 
 | //! <br> | 
 | //! | 
 | //! # Example | 
 | //! | 
 | //! ``` | 
 | //! use semver::{BuildMetadata, Prerelease, Version, VersionReq}; | 
 | //! | 
 | //! fn main() { | 
 | //!     let req = VersionReq::parse(">=1.2.3, <1.8.0").unwrap(); | 
 | //! | 
 | //!     // Check whether this requirement matches version 1.2.3-alpha.1 (no) | 
 | //!     let version = Version { | 
 | //!         major: 1, | 
 | //!         minor: 2, | 
 | //!         patch: 3, | 
 | //!         pre: Prerelease::new("alpha.1").unwrap(), | 
 | //!         build: BuildMetadata::EMPTY, | 
 | //!     }; | 
 | //!     assert!(!req.matches(&version)); | 
 | //! | 
 | //!     // Check whether it matches 1.3.0 (yes it does) | 
 | //!     let version = Version::parse("1.3.0").unwrap(); | 
 | //!     assert!(req.matches(&version)); | 
 | //! } | 
 | //! ``` | 
 | //! | 
 | //! <br><br> | 
 | //! | 
 | //! # Scope of this crate | 
 | //! | 
 | //! Besides Cargo, several other package ecosystems and package managers for | 
 | //! other languages also use SemVer: RubyGems/Bundler for Ruby, npm for | 
 | //! JavaScript, Composer for PHP, CocoaPods for Objective-C... | 
 | //! | 
 | //! The `semver` crate is specifically intended to implement Cargo's | 
 | //! interpretation of Semantic Versioning. | 
 | //! | 
 | //! Where the various tools differ in their interpretation or implementation of | 
 | //! the spec, this crate follows the implementation choices made by Cargo. If | 
 | //! you are operating on version numbers from some other package ecosystem, you | 
 | //! will want to use a different semver library which is appropriate to that | 
 | //! ecosystem. | 
 | //! | 
 | //! The extent of Cargo's SemVer support is documented in the *[Specifying | 
 | //! Dependencies]* chapter of the Cargo reference. | 
 | //! | 
 | //! [Specifying Dependencies]: https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html | 
 |  | 
 | #![doc(html_root_url = "https://docs.rs/semver/1.0.23")] | 
 | #![cfg_attr(doc_cfg, feature(doc_cfg))] | 
 | #![cfg_attr(all(not(feature = "std"), not(no_alloc_crate)), no_std)] | 
 | #![cfg_attr(not(no_unsafe_op_in_unsafe_fn_lint), deny(unsafe_op_in_unsafe_fn))] | 
 | #![cfg_attr(no_unsafe_op_in_unsafe_fn_lint, allow(unused_unsafe))] | 
 | #![cfg_attr(no_str_strip_prefix, allow(unstable_name_collisions))] | 
 | #![allow( | 
 |     clippy::cast_lossless, | 
 |     clippy::cast_possible_truncation, | 
 |     clippy::doc_markdown, | 
 |     clippy::incompatible_msrv, | 
 |     clippy::items_after_statements, | 
 |     clippy::manual_map, | 
 |     clippy::match_bool, | 
 |     clippy::missing_errors_doc, | 
 |     clippy::must_use_candidate, | 
 |     clippy::needless_doctest_main, | 
 |     clippy::ptr_as_ptr, | 
 |     clippy::redundant_else, | 
 |     clippy::semicolon_if_nothing_returned, // https://github.com/rust-lang/rust-clippy/issues/7324 | 
 |     clippy::similar_names, | 
 |     clippy::unnested_or_patterns, | 
 |     clippy::unseparated_literal_suffix, | 
 |     clippy::wildcard_imports | 
 | )] | 
 |  | 
 | #[cfg(not(no_alloc_crate))] | 
 | extern crate alloc; | 
 |  | 
 | mod backport; | 
 | mod display; | 
 | mod error; | 
 | mod eval; | 
 | mod identifier; | 
 | mod impls; | 
 | mod parse; | 
 |  | 
 | #[cfg(feature = "serde")] | 
 | mod serde; | 
 |  | 
 | use crate::identifier::Identifier; | 
 | use core::cmp::Ordering; | 
 | use core::str::FromStr; | 
 |  | 
 | #[allow(unused_imports)] | 
 | use crate::backport::*; | 
 |  | 
 | pub use crate::parse::Error; | 
 |  | 
 | /// **SemVer version** as defined by <https://semver.org>. | 
 | /// | 
 | /// # Syntax | 
 | /// | 
 | /// - The major, minor, and patch numbers may be any integer 0 through u64::MAX. | 
 | ///   When representing a SemVer version as a string, each number is written as | 
 | ///   a base 10 integer. For example, `1.0.119`. | 
 | /// | 
 | /// - Leading zeros are forbidden in those positions. For example `1.01.00` is | 
 | ///   invalid as a SemVer version. | 
 | /// | 
 | /// - The pre-release identifier, if present, must conform to the syntax | 
 | ///   documented for [`Prerelease`]. | 
 | /// | 
 | /// - The build metadata, if present, must conform to the syntax documented for | 
 | ///   [`BuildMetadata`]. | 
 | /// | 
 | /// - Whitespace is not allowed anywhere in the version. | 
 | /// | 
 | /// # Total ordering | 
 | /// | 
 | /// Given any two SemVer versions, one is less than, greater than, or equal to | 
 | /// the other. Versions may be compared against one another using Rust's usual | 
 | /// comparison operators. | 
 | /// | 
 | /// - The major, minor, and patch number are compared numerically from left to | 
 | /// right, lexicographically ordered as a 3-tuple of integers. So for example | 
 | /// version `1.5.0` is less than version `1.19.0`, despite the fact that | 
 | /// "1.19.0" < "1.5.0" as ASCIIbetically compared strings and 1.19 < 1.5 | 
 | /// as real numbers. | 
 | /// | 
 | /// - When major, minor, and patch are equal, a pre-release version is | 
 | ///   considered less than the ordinary release: version `1.0.0-alpha.1` is | 
 | ///   less than version `1.0.0`. | 
 | /// | 
 | /// - Two pre-releases of the same major, minor, patch are compared by | 
 | ///   lexicographic ordering of dot-separated components of the pre-release | 
 | ///   string. | 
 | /// | 
 | ///   - Identifiers consisting of only digits are compared | 
 | ///     numerically: `1.0.0-pre.8` is less than `1.0.0-pre.12`. | 
 | /// | 
 | ///   - Identifiers that contain a letter or hyphen are compared in ASCII sort | 
 | ///     order: `1.0.0-pre12` is less than `1.0.0-pre8`. | 
 | /// | 
 | ///   - Any numeric identifier is always less than any non-numeric | 
 | ///     identifier: `1.0.0-pre.1` is less than `1.0.0-pre.x`. | 
 | /// | 
 | /// Example: `1.0.0-alpha` < `1.0.0-alpha.1` < `1.0.0-alpha.beta` < `1.0.0-beta` < `1.0.0-beta.2` < `1.0.0-beta.11` < `1.0.0-rc.1` < `1.0.0` | 
 | #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash)] | 
 | pub struct Version { | 
 |     pub major: u64, | 
 |     pub minor: u64, | 
 |     pub patch: u64, | 
 |     pub pre: Prerelease, | 
 |     pub build: BuildMetadata, | 
 | } | 
 |  | 
 | /// **SemVer version requirement** describing the intersection of some version | 
 | /// comparators, such as `>=1.2.3, <1.8`. | 
 | /// | 
 | /// # Syntax | 
 | /// | 
 | /// - Either `*` (meaning "any"), or one or more comma-separated comparators. | 
 | /// | 
 | /// - A [`Comparator`] is an operator ([`Op`]) and a partial version, separated | 
 | ///   by optional whitespace. For example `>=1.0.0` or `>=1.0`. | 
 | /// | 
 | /// - Build metadata is syntactically permitted on the partial versions, but is | 
 | ///   completely ignored, as it's never relevant to whether any comparator | 
 | ///   matches a particular version. | 
 | /// | 
 | /// - Whitespace is permitted around commas and around operators. Whitespace is | 
 | ///   not permitted within a partial version, i.e. anywhere between the major | 
 | ///   version number and its minor, patch, pre-release, or build metadata. | 
 | #[derive(Clone, Eq, PartialEq, Hash, Debug)] | 
 | #[cfg_attr(no_const_vec_new, derive(Default))] | 
 | pub struct VersionReq { | 
 |     pub comparators: Vec<Comparator>, | 
 | } | 
 |  | 
 | /// A pair of comparison operator and partial version, such as `>=1.2`. Forms | 
 | /// one piece of a VersionReq. | 
 | #[derive(Clone, Eq, PartialEq, Hash, Debug)] | 
 | pub struct Comparator { | 
 |     pub op: Op, | 
 |     pub major: u64, | 
 |     pub minor: Option<u64>, | 
 |     /// Patch is only allowed if minor is Some. | 
 |     pub patch: Option<u64>, | 
 |     /// Non-empty pre-release is only allowed if patch is Some. | 
 |     pub pre: Prerelease, | 
 | } | 
 |  | 
 | /// SemVer comparison operator: `=`, `>`, `>=`, `<`, `<=`, `~`, `^`, `*`. | 
 | /// | 
 | /// # Op::Exact | 
 | /// -  **`=I.J.K`** — exactly the version I.J.K | 
 | /// -  **`=I.J`** — equivalent to `>=I.J.0, <I.(J+1).0` | 
 | /// -  **`=I`** — equivalent to `>=I.0.0, <(I+1).0.0` | 
 | /// | 
 | /// # Op::Greater | 
 | /// -  **`>I.J.K`** | 
 | /// -  **`>I.J`** — equivalent to `>=I.(J+1).0` | 
 | /// -  **`>I`** — equivalent to `>=(I+1).0.0` | 
 | /// | 
 | /// # Op::GreaterEq | 
 | /// -  **`>=I.J.K`** | 
 | /// -  **`>=I.J`** — equivalent to `>=I.J.0` | 
 | /// -  **`>=I`** — equivalent to `>=I.0.0` | 
 | /// | 
 | /// # Op::Less | 
 | /// -  **`<I.J.K`** | 
 | /// -  **`<I.J`** — equivalent to `<I.J.0` | 
 | /// -  **`<I`** — equivalent to `<I.0.0` | 
 | /// | 
 | /// # Op::LessEq | 
 | /// -  **`<=I.J.K`** | 
 | /// -  **`<=I.J`** — equivalent to `<I.(J+1).0` | 
 | /// -  **`<=I`** — equivalent to `<(I+1).0.0` | 
 | /// | 
 | /// # Op::Tilde ("patch" updates) | 
 | /// *Tilde requirements allow the **patch** part of the semver version (the third number) to increase.* | 
 | /// -  **`~I.J.K`** — equivalent to `>=I.J.K, <I.(J+1).0` | 
 | /// -  **`~I.J`** — equivalent to `=I.J` | 
 | /// -  **`~I`** — equivalent to `=I` | 
 | /// | 
 | /// # Op::Caret ("compatible" updates) | 
 | /// *Caret requirements allow parts that are **right of the first nonzero** part of the semver version to increase.* | 
 | /// -  **`^I.J.K`** (for I\>0) — equivalent to `>=I.J.K, <(I+1).0.0` | 
 | /// -  **`^0.J.K`** (for J\>0) — equivalent to `>=0.J.K, <0.(J+1).0` | 
 | /// -  **`^0.0.K`** — equivalent to `=0.0.K` | 
 | /// -  **`^I.J`** (for I\>0 or J\>0) — equivalent to `^I.J.0` | 
 | /// -  **`^0.0`** — equivalent to `=0.0` | 
 | /// -  **`^I`** — equivalent to `=I` | 
 | /// | 
 | /// # Op::Wildcard | 
 | /// -  **`I.J.*`** — equivalent to `=I.J` | 
 | /// -  **`I.*`** or **`I.*.*`** — equivalent to `=I` | 
 | #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)] | 
 | #[cfg_attr(not(no_non_exhaustive), non_exhaustive)] | 
 | pub enum Op { | 
 |     Exact, | 
 |     Greater, | 
 |     GreaterEq, | 
 |     Less, | 
 |     LessEq, | 
 |     Tilde, | 
 |     Caret, | 
 |     Wildcard, | 
 |  | 
 |     #[cfg(no_non_exhaustive)] // rustc <1.40 | 
 |     #[doc(hidden)] | 
 |     __NonExhaustive, | 
 | } | 
 |  | 
 | /// Optional pre-release identifier on a version string. This comes after `-` in | 
 | /// a SemVer version, like `1.0.0-alpha.1` | 
 | /// | 
 | /// # Examples | 
 | /// | 
 | /// Some real world pre-release idioms drawn from crates.io: | 
 | /// | 
 | /// - **[mio]** <code>0.7.0-<b>alpha.1</b></code> — the most common style | 
 | ///   for numbering pre-releases. | 
 | /// | 
 | /// - **[pest]** <code>1.0.0-<b>beta.8</b></code>, <code>1.0.0-<b>rc.0</b></code> | 
 | ///   — this crate makes a distinction between betas and release | 
 | ///   candidates. | 
 | /// | 
 | /// - **[sassers]** <code>0.11.0-<b>shitshow</b></code> — ???. | 
 | /// | 
 | /// - **[atomic-utils]** <code>0.0.0-<b>reserved</b></code> — a squatted | 
 | ///   crate name. | 
 | /// | 
 | /// [mio]: https://crates.io/crates/mio | 
 | /// [pest]: https://crates.io/crates/pest | 
 | /// [atomic-utils]: https://crates.io/crates/atomic-utils | 
 | /// [sassers]: https://crates.io/crates/sassers | 
 | /// | 
 | /// *Tip:* Be aware that if you are planning to number your own pre-releases, | 
 | /// you should prefer to separate the numeric part from any non-numeric | 
 | /// identifiers by using a dot in between. That is, prefer pre-releases | 
 | /// `alpha.1`, `alpha.2`, etc rather than `alpha1`, `alpha2` etc. The SemVer | 
 | /// spec's rule for pre-release precedence has special treatment of numeric | 
 | /// components in the pre-release string, but only if there are no non-digit | 
 | /// characters in the same dot-separated component. So you'd have `alpha.2` < | 
 | /// `alpha.11` as intended, but `alpha11` < `alpha2`. | 
 | /// | 
 | /// # Syntax | 
 | /// | 
 | /// Pre-release strings are a series of dot separated identifiers immediately | 
 | /// following the patch version. Identifiers must comprise only ASCII | 
 | /// alphanumerics and hyphens: `0-9`, `A-Z`, `a-z`, `-`. Identifiers must not be | 
 | /// empty. Numeric identifiers must not include leading zeros. | 
 | /// | 
 | /// # Total ordering | 
 | /// | 
 | /// Pre-releases have a total order defined by the SemVer spec. It uses | 
 | /// lexicographic ordering of dot-separated components. Identifiers consisting | 
 | /// of only digits are compared numerically. Otherwise, identifiers are compared | 
 | /// in ASCII sort order. Any numeric identifier is always less than any | 
 | /// non-numeric identifier. | 
 | /// | 
 | /// Example: `alpha` < `alpha.85` < `alpha.90` < `alpha.200` < `alpha.0a` < `alpha.1a0` < `alpha.a` < `beta` | 
 | #[derive(Default, Clone, Eq, PartialEq, Hash)] | 
 | pub struct Prerelease { | 
 |     identifier: Identifier, | 
 | } | 
 |  | 
 | /// Optional build metadata identifier. This comes after `+` in a SemVer | 
 | /// version, as in `0.8.1+zstd.1.5.0`. | 
 | /// | 
 | /// # Examples | 
 | /// | 
 | /// Some real world build metadata idioms drawn from crates.io: | 
 | /// | 
 | /// - **[libgit2-sys]** <code>0.12.20+<b>1.1.0</b></code> — for this | 
 | ///   crate, the build metadata indicates the version of the C libgit2 library | 
 | ///   that the Rust crate is built against. | 
 | /// | 
 | /// - **[mashup]** <code>0.1.13+<b>deprecated</b></code> — just the word | 
 | ///   "deprecated" for a crate that has been superseded by another. Eventually | 
 | ///   people will take notice of this in Cargo's build output where it lists the | 
 | ///   crates being compiled. | 
 | /// | 
 | /// - **[google-bigquery2]** <code>2.0.4+<b>20210327</b></code> — this | 
 | ///   library is automatically generated from an official API schema, and the | 
 | ///   build metadata indicates the date on which that schema was last captured. | 
 | /// | 
 | /// - **[fbthrift-git]** <code>0.0.6+<b>c7fcc0e</b></code> — this crate is | 
 | ///   published from snapshots of a big company monorepo. In monorepo | 
 | ///   development, there is no concept of versions, and all downstream code is | 
 | ///   just updated atomically in the same commit that breaking changes to a | 
 | ///   library are landed. Therefore for crates.io purposes, every published | 
 | ///   version must be assumed to be incompatible with the previous. The build | 
 | ///   metadata provides the source control hash of the snapshotted code. | 
 | /// | 
 | /// [libgit2-sys]: https://crates.io/crates/libgit2-sys | 
 | /// [mashup]: https://crates.io/crates/mashup | 
 | /// [google-bigquery2]: https://crates.io/crates/google-bigquery2 | 
 | /// [fbthrift-git]: https://crates.io/crates/fbthrift-git | 
 | /// | 
 | /// # Syntax | 
 | /// | 
 | /// Build metadata is a series of dot separated identifiers immediately | 
 | /// following the patch or pre-release version. Identifiers must comprise only | 
 | /// ASCII alphanumerics and hyphens: `0-9`, `A-Z`, `a-z`, `-`. Identifiers must | 
 | /// not be empty. Leading zeros *are* allowed, unlike any other place in the | 
 | /// SemVer grammar. | 
 | /// | 
 | /// # Total ordering | 
 | /// | 
 | /// Build metadata is ignored in evaluating `VersionReq`; it plays no role in | 
 | /// whether a `Version` matches any one of the comparison operators. | 
 | /// | 
 | /// However for comparing build metadatas among one another, they do have a | 
 | /// total order which is determined by lexicographic ordering of dot-separated | 
 | /// components. Identifiers consisting of only digits are compared numerically. | 
 | /// Otherwise, identifiers are compared in ASCII sort order. Any numeric | 
 | /// identifier is always less than any non-numeric identifier. | 
 | /// | 
 | /// Example: `demo` < `demo.85` < `demo.90` < `demo.090` < `demo.200` < `demo.1a0` < `demo.a` < `memo` | 
 | #[derive(Default, Clone, Eq, PartialEq, Hash)] | 
 | pub struct BuildMetadata { | 
 |     identifier: Identifier, | 
 | } | 
 |  | 
 | impl Version { | 
 |     /// Create `Version` with an empty pre-release and build metadata. | 
 |     /// | 
 |     /// Equivalent to: | 
 |     /// | 
 |     /// ``` | 
 |     /// # use semver::{BuildMetadata, Prerelease, Version}; | 
 |     /// # | 
 |     /// # const fn new(major: u64, minor: u64, patch: u64) -> Version { | 
 |     /// Version { | 
 |     ///     major, | 
 |     ///     minor, | 
 |     ///     patch, | 
 |     ///     pre: Prerelease::EMPTY, | 
 |     ///     build: BuildMetadata::EMPTY, | 
 |     /// } | 
 |     /// # } | 
 |     /// ``` | 
 |     pub const fn new(major: u64, minor: u64, patch: u64) -> Self { | 
 |         Version { | 
 |             major, | 
 |             minor, | 
 |             patch, | 
 |             pre: Prerelease::EMPTY, | 
 |             build: BuildMetadata::EMPTY, | 
 |         } | 
 |     } | 
 |  | 
 |     /// Create `Version` by parsing from string representation. | 
 |     /// | 
 |     /// # Errors | 
 |     /// | 
 |     /// Possible reasons for the parse to fail include: | 
 |     /// | 
 |     /// - `1.0` — too few numeric components. A SemVer version must have | 
 |     ///   exactly three. If you are looking at something that has fewer than | 
 |     ///   three numbers in it, it's possible it is a `VersionReq` instead (with | 
 |     ///   an implicit default `^` comparison operator). | 
 |     /// | 
 |     /// - `1.0.01` — a numeric component has a leading zero. | 
 |     /// | 
 |     /// - `1.0.unknown` — unexpected character in one of the components. | 
 |     /// | 
 |     /// - `1.0.0-` or `1.0.0+` — the pre-release or build metadata are | 
 |     ///   indicated present but empty. | 
 |     /// | 
 |     /// - `1.0.0-alpha_123` — pre-release or build metadata have something | 
 |     ///   outside the allowed characters, which are `0-9`, `A-Z`, `a-z`, `-`, | 
 |     ///   and `.` (dot). | 
 |     /// | 
 |     /// - `23456789999999999999.0.0` — overflow of a u64. | 
 |     pub fn parse(text: &str) -> Result<Self, Error> { | 
 |         Version::from_str(text) | 
 |     } | 
 |  | 
 |     /// Compare the major, minor, patch, and pre-release value of two versions, | 
 |     /// disregarding build metadata. Versions that differ only in build metadata | 
 |     /// are considered equal. This comparison is what the SemVer spec refers to | 
 |     /// as "precedence". | 
 |     /// | 
 |     /// # Example | 
 |     /// | 
 |     /// ``` | 
 |     /// use semver::Version; | 
 |     /// | 
 |     /// let mut versions = [ | 
 |     ///     "1.20.0+c144a98".parse::<Version>().unwrap(), | 
 |     ///     "1.20.0".parse().unwrap(), | 
 |     ///     "1.0.0".parse().unwrap(), | 
 |     ///     "1.0.0-alpha".parse().unwrap(), | 
 |     ///     "1.20.0+bc17664".parse().unwrap(), | 
 |     /// ]; | 
 |     /// | 
 |     /// // This is a stable sort, so it preserves the relative order of equal | 
 |     /// // elements. The three 1.20.0 versions differ only in build metadata so | 
 |     /// // they are not reordered relative to one another. | 
 |     /// versions.sort_by(Version::cmp_precedence); | 
 |     /// assert_eq!(versions, [ | 
 |     ///     "1.0.0-alpha".parse().unwrap(), | 
 |     ///     "1.0.0".parse().unwrap(), | 
 |     ///     "1.20.0+c144a98".parse().unwrap(), | 
 |     ///     "1.20.0".parse().unwrap(), | 
 |     ///     "1.20.0+bc17664".parse().unwrap(), | 
 |     /// ]); | 
 |     /// | 
 |     /// // Totally order the versions, including comparing the build metadata. | 
 |     /// versions.sort(); | 
 |     /// assert_eq!(versions, [ | 
 |     ///     "1.0.0-alpha".parse().unwrap(), | 
 |     ///     "1.0.0".parse().unwrap(), | 
 |     ///     "1.20.0".parse().unwrap(), | 
 |     ///     "1.20.0+bc17664".parse().unwrap(), | 
 |     ///     "1.20.0+c144a98".parse().unwrap(), | 
 |     /// ]); | 
 |     /// ``` | 
 |     pub fn cmp_precedence(&self, other: &Self) -> Ordering { | 
 |         Ord::cmp( | 
 |             &(self.major, self.minor, self.patch, &self.pre), | 
 |             &(other.major, other.minor, other.patch, &other.pre), | 
 |         ) | 
 |     } | 
 | } | 
 |  | 
 | impl VersionReq { | 
 |     /// A `VersionReq` with no constraint on the version numbers it matches. | 
 |     /// Equivalent to `VersionReq::parse("*").unwrap()`. | 
 |     /// | 
 |     /// In terms of comparators this is equivalent to `>=0.0.0`. | 
 |     /// | 
 |     /// Counterintuitively a `*` VersionReq does not match every possible | 
 |     /// version number. In particular, in order for *any* `VersionReq` to match | 
 |     /// a pre-release version, the `VersionReq` must contain at least one | 
 |     /// `Comparator` that has an explicit major, minor, and patch version | 
 |     /// identical to the pre-release being matched, and that has a nonempty | 
 |     /// pre-release component. Since `*` is not written with an explicit major, | 
 |     /// minor, and patch version, and does not contain a nonempty pre-release | 
 |     /// component, it does not match any pre-release versions. | 
 |     #[cfg(not(no_const_vec_new))] // rustc <1.39 | 
 |     pub const STAR: Self = VersionReq { | 
 |         comparators: Vec::new(), | 
 |     }; | 
 |  | 
 |     /// Create `VersionReq` by parsing from string representation. | 
 |     /// | 
 |     /// # Errors | 
 |     /// | 
 |     /// Possible reasons for the parse to fail include: | 
 |     /// | 
 |     /// - `>a.b` — unexpected characters in the partial version. | 
 |     /// | 
 |     /// - `@1.0.0` — unrecognized comparison operator. | 
 |     /// | 
 |     /// - `^1.0.0, ` — unexpected end of input. | 
 |     /// | 
 |     /// - `>=1.0 <2.0` — missing comma between comparators. | 
 |     /// | 
 |     /// - `*.*` — unsupported wildcard syntax. | 
 |     pub fn parse(text: &str) -> Result<Self, Error> { | 
 |         VersionReq::from_str(text) | 
 |     } | 
 |  | 
 |     /// Evaluate whether the given `Version` satisfies the version requirement | 
 |     /// described by `self`. | 
 |     pub fn matches(&self, version: &Version) -> bool { | 
 |         eval::matches_req(self, version) | 
 |     } | 
 | } | 
 |  | 
 | /// The default VersionReq is the same as [`VersionReq::STAR`]. | 
 | #[cfg(not(no_const_vec_new))] | 
 | impl Default for VersionReq { | 
 |     fn default() -> Self { | 
 |         VersionReq::STAR | 
 |     } | 
 | } | 
 |  | 
 | impl Comparator { | 
 |     pub fn parse(text: &str) -> Result<Self, Error> { | 
 |         Comparator::from_str(text) | 
 |     } | 
 |  | 
 |     pub fn matches(&self, version: &Version) -> bool { | 
 |         eval::matches_comparator(self, version) | 
 |     } | 
 | } | 
 |  | 
 | impl Prerelease { | 
 |     pub const EMPTY: Self = Prerelease { | 
 |         identifier: Identifier::empty(), | 
 |     }; | 
 |  | 
 |     pub fn new(text: &str) -> Result<Self, Error> { | 
 |         Prerelease::from_str(text) | 
 |     } | 
 |  | 
 |     pub fn as_str(&self) -> &str { | 
 |         self.identifier.as_str() | 
 |     } | 
 |  | 
 |     pub fn is_empty(&self) -> bool { | 
 |         self.identifier.is_empty() | 
 |     } | 
 | } | 
 |  | 
 | impl BuildMetadata { | 
 |     pub const EMPTY: Self = BuildMetadata { | 
 |         identifier: Identifier::empty(), | 
 |     }; | 
 |  | 
 |     pub fn new(text: &str) -> Result<Self, Error> { | 
 |         BuildMetadata::from_str(text) | 
 |     } | 
 |  | 
 |     pub fn as_str(&self) -> &str { | 
 |         self.identifier.as_str() | 
 |     } | 
 |  | 
 |     pub fn is_empty(&self) -> bool { | 
 |         self.identifier.is_empty() | 
 |     } | 
 | } |