Crate portable_atomic_util Copy item path

Synchronization primitives built with portable-atomic.

• Provide Arc. (optional, requires the std or alloc feature)
• Provide task::Wake. (optional, requires the std or alloc feature)

See #1 for other primitives being considered for addition to this crate.

§Optional features

• std
  Use std.

  Note:

  • This implicitly enables the alloc feature.

• alloc
  Use alloc.

  Note:

  • The MSRV when this feature is enabled and the std feature is not enabled is Rust 1.36 that alloc crate stabilized.

§Optional cfg

One of the ways to enable cfg is to set rustflags in the cargo config:

# .cargo/config.toml
[target.<target>]
rustflags = ["--cfg", "portable_atomic_unstable_coerce_unsized"]

Or set environment variable:

RUSTFLAGS="--cfg portable_atomic_unstable_coerce_unsized" cargo ...

• --cfg portable_atomic_unstable_coerce_unsized
  Support coercing of Arc<T> to Arc<U> as in std::sync::Arc.

  This cfg requires Rust nightly because this coercing requires unstable CoerceUnsized trait.

  See this issue comment for another known workaround.

  Note: This cfg is unstable and outside of the normal semver guarantees and minor or patch versions of portable-atomic-util may make breaking changes to them at any time.