[stdalign.h.syn]

The contents of the C++ header <stdalign.h> are the same as the C standard library header <stdalign.h>, with the following changes: The header <stdalign.h> does not define a macro named alignas.

17 Language support library [support]

17.15 C headers [support.c.headers]

17.15.4 Header <stdalign.h> synopsis [stdalign.h.syn]