* include/std/string_view (basic_string_view::copy): Use traits to
	copy.
	* testsuite/21_strings/basic_string_view/operations/copy/char/2.cc:
	New test.
	* testsuite/21_strings/basic_string_view/operations/copy/wchar_t/2.cc:
	New test.

From-SVN: r266269