Module hint 

Hints to compiler that affects how code should be emitted or optimized.

Hints may be compile time or runtime.

Functions

assert_unchecked^⚠

Makes a soundness promise to the compiler that cond holds.

select_unpredictable

Returns either true_val or false_val depending on the value of condition, with a hint to the compiler that condition is unlikely to be correctly predicted by a CPU’s branch predictor.

unreachable_unchecked^⚠

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