function is the wide-character equivalent of the
It copies the wide-character string pointed to by src,
including the terminating L'\0' character, to the array pointed to by
The strings may not overlap.
The programmer must ensure that there
is room for at least wcslen(src)+1
wide characters at dest.
returns a pointer to the end of the wide-character string
dest, that is, a pointer to the terminating L'\0' character.