-int argmatch (char const *arg, char const *const *arglist,
- char const *vallist, size_t valsize);
-int argcasematch (char const *arg, char const *const *arglist,
- char const *vallist, size_t valsize);
+ptrdiff_t argmatch (char const *arg, char const *const *arglist,
+ char const *vallist, size_t valsize);