2013-11-21 Edward Smith-Rowland <3dw4rd@verizon.net>
* include/experimental/string_view: Rep empty string with unit-length
static constexpr string. Uncomment _GLIBCXX_VISIBILITY. Enforce
invariant of no nullptr string pointer.
* include/experimental/string_view.tcc: Ditto.
* testsuite/experimental/string_view/cons/char/1.cc: data() for empty
string_view is no longer nullptr.
* testsuite/experimental/string_view/cons/wchar_t/1.cc: Ditto.
* testsuite/experimental/string_view/operations/data/char/1.cc: Ditto.
* testsuite/experimental/string_view/operations/data/wchar_t/1.cc:
Ditto.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@205213 138bc75d-0d04-0410-961f-82ee72b054a4