1 #include <uchar.h>
2 #include <wchar.h>
3
mbrtoc16(char16_t * restrict pc16,const char * restrict s,size_t n,mbstate_t * restrict ps)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 }
31