wcstombs
size_t wcstombs(char * __restrict, const wchar_t * __restrict, size_t);
ATF_REQUIRE(wcstombs(dstbuf, srcbuf, sizeof(dstbuf)) == 7);
ATF_REQUIRE(wcstombs(dstbuf, srcbuf, sizeof(dstbuf)) == 5);
ATF_REQUIRE(wcstombs(dstbuf, srcbuf, 4) == 4);
ATF_REQUIRE(wcstombs(NULL, srcbuf, sizeof(dstbuf)) == 5);
ATF_REQUIRE(wcstombs(dstbuf, srcbuf, sizeof(dstbuf)) == 5);
ATF_REQUIRE(wcstombs(NULL, srcbuf, 0) == 5);
ATF_REQUIRE(wcstombs(dstbuf, srcbuf, sizeof(dstbuf)) == 0);
ATF_REQUIRE(wcstombs(dstbuf, srcbuf, 0) == 0);