c/string/wide/wmemcpy

@1@ Copies exactly successive wide characters from the wide character array pointed to by  to the wide character array pointed to by. If the objects overlap, the behavior is undefined. If is zero, the function does nothing. @2@ Same as, except that the following errors are detected at runtime and call the currently installed constraint handler function:
 * or is a null pointer
 * or is greater than
 * is greater than (overflow would occur)
 * overlap would occur between the source and the destination arrays

Return value
@1@ returns a copy of @2@ returns zero on success, returns non-zero on error. Also, on error, fills the entire up to and not including  with null wide characters,  (unless  is null or  is greater than )