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`wctrans'--get wide-character translation type

     #include <wctype.h>
     wctrans_t wctrans(const char *C);
`wctrans' is a function which takes a string C and gives back the
appropriate wctrans_t type value associated with the string, if one
exists.  The following values are guaranteed to be recognized:
"tolower" and "toupper".
`wctrans' returns 0 and sets `errno' to `EINVAL' if the given name is
invalid.  Otherwise, it returns a valid non-zero wctrans_t value.
`wctrans' is C99.
   No supporting OS subroutines are required.