Module `ub_checks`

Provides the assert_unsafe_precondition macro as well as some utility functions that cover common preconditions.

Functions

check_language_ub Determines whether we should check for language UB.
check_library_ub Returns whether we should perform some UB-checking at runtime. This eventually evaluates to cfg!(ub_checks), but behaves different from cfg! when mixing crates built with different flags: if the crate has UB checks enabled or carries the #[rustc_preserve_ub_checks] attribute, evaluation is delayed until monomorphization (or until the call gets inlined into a crate that does not delay evaluation further); otherwise it can happen any time.
is_valid_allocation_size
maybe_is_aligned Checks whether ptr is properly aligned with respect to the given alignment.
maybe_is_aligned_and_not_null Checks whether ptr is properly aligned with respect to the given alignment, and if is_zst == false, that ptr is not null.
maybe_is_nonoverlapping Checks whether the regions of memory starting at src and dst of size count * size do not overlap.

assert_unsafe_precondition Checks that the preconditions of an unsafe function are followed.