[PATCH 2/2] libstdc++: Implement LWG 3533 changes to foo_view::iterator::base()

[Jonathan Wakely]

On 05/05/21 16:23 -0400, Patrick Palka via Libstdc++ wrote:
>Tested on x86_64-pc-linux-gnu, does this look OK for trunk/10/11?

Yes, thanks.

>libstdc++-v3/ChangeLog:
>
>	* include/std/ranges (filter_view::_Iterator::base): Make the
>	const& overload return a const reference and remove its
>	constraint as per LWG 3533. Make unconditionally noexcept.
>	(transform_view::_Iterator::base): Likewise.
>	(elements_view::_Iterator::base): Likewise.
>---
> libstdc++-v3/include/std/ranges | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
>diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
>index 7075fa3ae6e..bc11505c167 100644
>--- a/libstdc++-v3/include/std/ranges
>+++ b/libstdc++-v3/include/std/ranges
>@@ -1199,9 +1199,8 @@ namespace views::__adaptor
> 	    _M_parent(__parent)
> 	{ }
>
>-	constexpr _Vp_iter
>-	base() const &
>-	  requires copyable<_Vp_iter>
>+	constexpr const _Vp_iter&
>+	base() const & noexcept
> 	{ return _M_current; }
>
> 	constexpr _Vp_iter
>@@ -1467,9 +1466,8 @@ namespace views::__adaptor
> 	    : _M_current(std::move(__i._M_current)), _M_parent(__i._M_parent)
> 	  { }
>
>-	  constexpr _Base_iter
>-	  base() const &
>-	    requires copyable<_Base_iter>
>+	  constexpr const _Base_iter&
>+	  base() const & noexcept
> 	  { return _M_current; }
>
> 	  constexpr _Base_iter
>@@ -3403,8 +3401,8 @@ namespace views::__adaptor
> 	: _M_base(std::move(base))
>       { }
>
>-      constexpr _Vp
>-      base() const& requires copy_constructible<_Vp>
>+      constexpr const _Vp&
>+      base() const & noexcept
>       { return _M_base; }
>
>       constexpr _Vp
>-- 
>2.31.1.442.g7e39198978
>