* testsuite/26_numerics/slice_array_assignment.cc (main): New test.

    * testsuite/26_numerics/slice_array_assignment.cc (main): New test.

        * include/bits/slice_array.h (slice_array<>::operator=): Make
        public and implement.
        (slice_array<>::slice_array): Make copy-constructor public.

        * include/bits/valarray_array.h (__valarray_copy): Add another
        overload to copy between strided arrays.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@43352 138bc75d-0d04-0410-961f-82ee72b054a4