2 * This code was written by Rich Felker in 2010; no copyright is claimed.
3 * This code is in the public domain. Attribution is appreciated but
11 int mbtowc(wchar_t *restrict wc, const char *restrict src, size_t n)
14 const unsigned char *s = (const void *)src;
18 if (!wc) wc = (void *)&wc;
20 if (*s < 0x80) return !!(*wc = *s);
21 if (*s-SA > SB-SA) goto ilseq;
24 /* Avoid excessive checks against n: If shifting the state n-1
25 * times does not clear the high bit, then the value of n is
26 * insufficient to read a character */
27 if (n<4 && ((c<<(6*n-6)) & (1U<<31))) goto ilseq;
29 if (OOB(c,*s)) goto ilseq;
36 if (*s-0x80u >= 0x40) goto ilseq;
43 if (*s-0x80u >= 0x40) goto ilseq;
44 *wc = c<<6 | *s++-0x80;