github.com/afumu/libc@v0.0.6/musl/src/multibyte/mbrtoc16.c (about)

     1  #include <uchar.h>
     2  #include <wchar.h>
     3  
     4  size_t mbrtoc16(char16_t *restrict pc16, const char *restrict s, size_t n, mbstate_t *restrict ps)
     5  {
     6  	static unsigned internal_state;
     7  	if (!ps) ps = (void *)&internal_state;
     8  	unsigned *pending = (unsigned *)ps;
     9  
    10  	if (!s) return mbrtoc16(0, "", 1, ps);
    11  
    12  	/* mbrtowc states for partial UTF-8 characters have the high bit set;
    13  	 * we use nonzero states without high bit for pending surrogates. */
    14  	if ((int)*pending > 0) {
    15   		if (pc16) *pc16 = *pending;
    16  		*pending = 0;
    17  		return -3;
    18  	}
    19  
    20  	wchar_t wc;
    21  	size_t ret = mbrtowc(&wc, s, n, ps);
    22  	if (ret <= 4) {
    23  		if (wc >= 0x10000) {
    24  			*pending = (wc & 0x3ff) + 0xdc00;
    25  			wc = 0xd7c0 + (wc >> 10);
    26  		}
    27  		if (pc16) *pc16 = wc;
    28  	}
    29  	return ret;
    30  }