bwsalloc
struct bwstring *ret = bwsalloc(BWSLEN(s));
return ((len == 0) ? bwsalloc(0) : NULL);
ret = bwsalloc(len);
ret = bwsalloc(len);
struct bwstring *bwsalloc(size_t sz);
ret = bwsalloc(sz);
ret = bwsalloc(0);