Description

   The wcsxfrm function transforms the string pointed to by ws2
   and stores the resulting string in the array pointed to by ws1.
   No more than maxchar wide characters, including the null wide
   terminator, are placed into the array pointed to by ws1.

   If the value of maxchar is less than the required size to store
   the transformed string (including the terminating null), the
   contents of the array pointed to by ws1 is indeterminate. In such
   a case, the function returns the size of the transformed string.

   If maxchar is 0, then, ws1 is allowed to be a NULL pointer, and
   the function returns the required size of the ws1 array before
   making the transformation.

   The wide-character string comparison functions, wcscoll and
   wcscmp, can produce different results given the same two wide-
   character strings to compare. This is because wcscmp does a
   straightforward comparison of the code point values of the
   characters in the strings, whereas wcscoll uses the locale
   information to do the comparison. Depending on the locale, the
   wcscoll comparison can be a multipass operation, which is slower
   than wcscmp.

   The wcsxfrm function transforms wide-character strings in such
   a way that if you pass two transformed strings to the wcscmp
   function, the result is the same as passing the two original
   strings to the wcscoll function. The wcsxfrm function is useful
   in applications that need to do a large number of comparisons on
   the same wide-character strings using wcscoll. In this case, it
   may be more efficient (depending on the locale) to transform the
   strings once using wcsxfrm and then use the wcscmp function to do
   comparisons.