libstdc++: Define split_view::_InnerIter::base as per P2210

libstdc++-v3/ChangeLog:

	* include/std/ranges (split_view::_InnerIter::base): Define as
	per P2210.

(cherry picked from commit 85a594f7dc8ea5c765e136f162debb668139ebd4)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 1f43cad1d7317eb3c584b1720ff35a9cad48bf76..c507862660bcf7f4685f1fdd93d6cc1ed918fa73 100644 (file)
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -3021,6 +3021,14 @@ namespace views::__adaptor
            : _M_i(std::move(__i))
          { }
 
+         constexpr iterator_t<_Base>
+         base() const& requires copyable<iterator_t<_Base>>
+         { return _M_i_current(); }
+
+         constexpr iterator_t<_Base>
+         base() &&
+         { return std::move(_M_i_current()); }
+
          constexpr decltype(auto)
          operator*() const
          { return *_M_i_current(); }