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.
The contents of the C++ header <stdbool.h> are the same as the C
standard library header <stdbool.h>, with the following changes:
The header <stdbool.h> does not
define macros named bool, true, or false.
Every C header
other than
<complex.h>,
<iso646.h>,
<stdalign.h>, <stdbool.h>, and
<tgmath.h>,
each of
which has a name of the form
<name.h>,
behaves as if each name placed in the standard library namespace by
the corresponding
<cname>
header is placed within
the global namespace scope,
except for the functions described in [sf.cmath],
the declaration of std::byte ([cstddef.syn]), and
the functions and function templates described in [support.types.byteops].
It is unspecified whether these names are first declared or defined within
namespace scope ([basic.scope.namespace]) of the namespace
std and are then injected into the global namespace scope by
explicit using-declarations ([namespace.udecl]).