wmemchar for unix

[monarch_dodra]

For performance reasons, I need a "w" version of memchr.

C defines wmemchr as:
wchar_t * wmemchr ( const wchar_t *, wchar_t, size_t );

Unfortunatly, on unix, "wchar_t" is defined a *4* bytes long,
making wmemchr, effectivelly, "dmemchr".

Are there any "2 byte" alternatives for wmemchr on unix?