Module std::hint

1.27.0 · source ·
Expand description

Hints to compiler that affects how code should be emitted or optimized. Hints may be compile time or runtime.


  • An identity function that hints to the compiler to be maximally pessimistic about what black_box could do.
  • Emits a machine instruction to signal the processor that it is running in a busy-wait spin-loop (“spin lock”).
  • Informs the compiler that the site which is calling this function is not reachable, possibly enabling further optimizations.
  • assert_uncheckedExperimental
    Makes a soundness promise to the compiler that cond holds.
  • must_useExperimental
    An identity function that causes an unused_must_use warning to be triggered if the given value is not used (returned, stored in a variable, etc) by the caller.