--- /dev/null
+/* mbrtowc(
+ wchar_t *restrict pwc,
+ const char *restrict s,
+ size_t n,
+ mbstate_t *restrict ps);
+
+ This file is part of the Public Domain C Library (PDCLib).
+ Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <wchar.h>
+#ifndef REGTEST
+#include <errno.h>
+#include <stdint.h>
+#include <assert.h>
+#include <_PDCLIB_encoding.h>
+#include <_PDCLIB_locale.h>
+
+size_t mbrtowc_l(
+ wchar_t *restrict pwc,
+ const char *restrict s,
+ size_t n,
+ mbstate_t *restrict ps,
+ locale_t restrict l
+)
+{
+ size_t res;
+
+ if(s == NULL) {
+ s = "";
+ n = 1;
+ }
+
+ if(ps->_PendState == _PendPrefix) {
+ res = _PDCLIB_mbrtocwc_l(pwc, &ps->_PendChar, 1, ps, l);
+ switch(res) {
+ case 0:
+ // Converted the NUL character
+ ps->_PendState = _PendClear;
+ return 0;
+
+ case 1:
+ // Successful conversion
+ ps->_PendChar = *s;
+ return 1;
+
+ case (size_t) -1:
+ // Illegal sequence. mbrtocwc has already set errno.
+ return (size_t) -1;
+
+ case (size_t) -3:
+ assert(!"Codec had buffered two characters");
+ _PDCLIB_UNREACHABLE;
+ return 0;
+
+ case (size_t) -2:
+ // Incomplete character, continue
+ break;
+ }
+ }
+
+ // _PendClear state
+ res = _PDCLIB_mbrtocwc_l(pwc, s, n, ps, l);
+ switch(res) {
+ case (size_t) -3:
+ // Converted entirely from internal state
+ ps->_PendChar = *s;
+ ps->_PendState = _PendPrefix;
+ return 1;
+ default:
+ return res;
+ }
+}
+
+size_t mbrtowc(
+ wchar_t *restrict pwc,
+ const char *restrict s,
+ size_t n,
+ mbstate_t *restrict ps
+)
+{
+ return mbrtowc_l(pwc, s, n, ps, _PDCLIB_threadlocale());
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+ TESTCASE( NO_TESTDRIVER );
+ return TEST_RESULTS;
+}
+#endif