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.