wmemchr

wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n); [not in C++]
const wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n); [C++ only]
wchar_t *wmemchr(wchar_t *s, wchar_t c, size_t n); [C++ only]

The function searches for the first element of an array beginning at the address s with size n, that equals c. If successful, it returns the address of the matching element; otherwise, it returns a null pointer.