1#include <wchar.h>
2
3size_t wcsrtombs(char *restrict s, const wchar_t **restrict ws, size_t n, mbstate_t *restrict st)
4{
5 const wchar_t *ws2;
6 char buf[4];
7 size_t N = n, l;
8 if (!s) {
9 for (n=0, ws2=*ws; *ws2; ws2++) {
10 if (*ws2 >= 0x80u) {
11 l = wcrtomb(buf, *ws2, 0);
12 if (!(l+1)) return -1;
13 n += l;
14 } else n++;
15 }
16 return n;
17 }
18 while (n>=4) {
19 if (**ws-1u >= 0x7fu) {
20 if (!**ws) {
21 *s = 0;
22 *ws = 0;
23 return N-n;
24 }
25 l = wcrtomb(s, **ws, 0);
26 if (!(l+1)) return -1;
27 s += l;
28 n -= l;
29 } else {
30 *s++ = **ws;
31 n--;
32 }
33 (*ws)++;
34 }
35 while (n) {
36 if (**ws-1u >= 0x7fu) {
37 if (!**ws) {
38 *s = 0;
39 *ws = 0;
40 return N-n;
41 }
42 l = wcrtomb(buf, **ws, 0);
43 if (!(l+1)) return -1;
44 if (l>n) return N-n;
45 wcrtomb(s, **ws, 0);
46 s += l;
47 n -= l;
48 } else {
49 *s++ = **ws;
50 n--;
51 }
52 (*ws)++;
53 }
54 return N;
55}