Annex C (informative) Compatibility [diff]

C.8 C standard library [diff.library]

C.8.3 Modifications to definitions []

C.8.3.2 Type wchar_t [diff.wchar.t]

The type wchar_t is a distinct type rather than a typedef to an existing integral type.
The token wchar_t is a keyword in C++ ([lex.key]).
It does not appear as a macro or type name defined in any of <cstddef>, <cstdlib>, or <cwchar>.