Function core::intrinsics::raw_eq

pub unsafe extern "rust-intrinsic" fn raw_eq<T>(a: &T, b: &T) -> bool

🔬 This is a nightly-only experimental API. (core_intrinsics)

Determines whether the raw bytes of the two values are equal.

This is particularly handy for arrays, since it allows things like just comparing i96s instead of forcing allocas for [6 x i16].

Above some backend-decided threshold this will emit calls to memcmp, like slice equality does, instead of causing massive code size.

Safety

It’s UB to call this if any of the bytes in *a or *b are uninitialized or carry a pointer value. Note that this is a stricter criterion than just the values being fully-initialized: if T has padding, it’s UB to call this intrinsic.

(The implementation is allowed to branch on the results of comparisons, which is UB if any of their inputs are undef.)