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;
21 if (*s < 0x80) return !!(*wc = *s);
22 if (*s-SA > SB-SA) goto ilseq;
25 /* Avoid excessive checks against n: If shifting the state n-1
26 * times does not clear the high bit, then the value of n is
27 * insufficient to read a character */
28 if (n<4 && ((c<<(6*n-6)) & (1U<<31))) goto ilseq;
30 if (OOB(c,*s)) goto ilseq;
37 if (*s-0x80u >= 0x40) goto ilseq;
44 if (*s-0x80u >= 0x40) goto ilseq;
45 *wc = c<<6 | *s++-0x80;