Is there a list of all cfg features?

Question

Rust has the ability to check configuration at build time with, e.g., #[cfg(target_os = "linux")] or if cfg!(target_os = "linux") {...}, where target_os is a feature.

Is there a list of all (or, at least, commonly used) features that can be checked in Rust?

---

See related question regarding attributes Is there an exhaustive list of standard attributes anywhere?.

Answer 1

The "Conditional compilation" section of the Reference has a list of configurations that must be defined (as of Rust 1.14):

• target_arch with values like:
  • x86
  • x86_64
  • mips
  • powerpc
  • powerpc64
  • arm
  • aarch64
• target_os with values like:
  • windows
  • macos
  • ios
  • linux
  • android
  • freebsd
  • dragonfly
  • bitrig
  • openbsd
  • netbsd
• target_family with values like:
  • unix
  • windows
• unix (shortcut for target_family)
• windows (shortcut for target_family)
• target_env with values like:
  • gnu
  • msvc
  • musl
  • "" (empty string)
• target_endian with values:
  • little
  • big
• target_pointer_width with values like:
  • 32
  • 64
• target_has_atomic with values like:
  • 8
  • 16
  • 32
  • 64
  • ptr
• target_vendor with values like:
  • apple
  • pc
  • unknown
• test
• debug_assertions

Answer 2

You can also use this command: rustc --print target-list.

Each triple are formatted as follows: {arch}-{vendor}-{sys}-{abi}.

For example, the triple 'arm-unknown-linux-gnueabihf' refers to:

1. architecture: arm
2. vendor: unknown. In this case, no vendor was specified.
3. system: linux
4. ABI: gnueabihf

Answer 3

See also https://internals.rust-lang.org/t/all-the-rust-features/4322 for a comprehensive list of features.

Bear in mind that some / most of the features won't be stabilized so will only be available in nightly for some time and are subject to breaking improvements / upgrades until they are either stabilized or discontinued.

Features in rust nightly is survival of the fittest.