@JensGustedt @wdtz So #C23 adds #memalignment (), defined in <stdlib.h> as a regular function (think side-effects and correctness); it takes the 2's complement negation of the input expressed as a #uintptr_t and masks it against the input. https://cgit.freebsd.org/src/tree/lib/libc/stdlib/memalignment.c #FreeBSD picks it up in #libc from 15.1 and up, so it won't be in the man index until the release: https://www.freebsd.org/releases/15.1R/schedule/ #languagelawyering