1#include <wchar.h>23#undef wcsncat45wchar_t *6wcsncat(wchar_t *restrict s1, const wchar_t *restrict s2, size_t n)7{8 wchar_t *ret;910 for (ret = s1; *s1; ++s1)11 ;12 while (n-- > 0 && *s2)13 *s1++ = *s2++;14 *s1 = '\0';1516 return ret;1718}