src/lib.rs

//! Asynchronous channels.
//!
//! This crate provides channels that can be used to communicate between
//! asynchronous tasks.
//!
//! All items of this library are only available when the `std` or `alloc` feature of this
//! library is activated, and it is activated by default.

#![cfg_attr(feature = "cfg-target-has-atomic", feature(cfg_target_has_atomic))]

#![cfg_attr(not(feature = "std"), no_std)]

#![warn(missing_docs, missing_debug_implementations, rust_2018_idioms, unreachable_pub)]
// It cannot be included in the published code because this lints have false positives in the minimum required version.
#![cfg_attr(test, warn(single_use_lifetimes))]
#![warn(clippy::all)]

// mem::take requires Rust 1.40, matches! requires Rust 1.42
// Can be removed if the minimum supported version increased or if https://github.com/rust-lang/rust-clippy/issues/3941
// get's implemented.
#![allow(clippy::mem_replace_with_default, clippy::match_like_matches_macro)]

#![doc(test(attr(deny(warnings), allow(dead_code, unused_assignments, unused_variables))))]

#![doc(html_root_url = "https://docs.rs/futures-channel/0.3.7")]

#[cfg(all(feature = "cfg-target-has-atomic", not(feature = "unstable")))]
compile_error!("The `cfg-target-has-atomic` feature requires the `unstable` feature as an explicit opt-in to unstable features");

macro_rules! cfg_target_has_atomic {
    ($($item:item)*) => {$(
        #[cfg_attr(feature = "cfg-target-has-atomic", cfg(target_has_atomic = "ptr"))]
        $item
    )*};
}

cfg_target_has_atomic! {
    #[cfg(feature = "alloc")]
    extern crate alloc;

    #[cfg(feature = "alloc")]
    mod lock;
    #[cfg(feature = "std")]
    pub mod mpsc;
    #[cfg(feature = "alloc")]
    pub mod oneshot;
}