Module core::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.


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.

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.