Module core::hint

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

Functions

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.

black_box

An identity function that hints to the compiler to be maximally pessimistic about what black_box could do.

spin_loop

Emits a machine instruction to signal the processor that it is running in a busy-wait spin-loop (“spin lock”).

unreachable_unchecked^⚠

Informs the compiler that the site which is calling this function is not reachable, possibly enabling further optimizations.