Annex C (informative) Compatibility [diff]

C.7 C standard library [diff.library]

C.7.3 Modifications to definitions [diff.mods.to.definitions]

C.7.3.1 Types char16_­t and char32_­t [diff.char16]

The types char16_­t and char32_­t are distinct types rather than typedefs to existing integral types.
The tokens char16_­t and char32_­t are keywords in C++ ([lex.key]).
They do not appear as macro or type names defined in <cuchar>.