[libcxx-commits] [libcxx] [libc++] Simplify the implementation of std::get for pairs (PR #114984)

[Louis Dionne via libcxx-commits]

================
@@ -633,42 +633,42 @@ get(const pair<_T1, _T2>&& __p) _NOEXCEPT {
 #if _LIBCPP_STD_VER >= 14
 template <class _T1, class _T2>
 inline _LIBCPP_HIDE_FROM_ABI constexpr _T1& get(pair<_T1, _T2>& __p) _NOEXCEPT {
-  return __get_pair<0>::get(__p);
+  return __p.first;
 }
 
 template <class _T1, class _T2>
 inline _LIBCPP_HIDE_FROM_ABI constexpr _T1 const& get(pair<_T1, _T2> const& __p) _NOEXCEPT {
-  return __get_pair<0>::get(__p);
+  return __p.first;
 }
 
 template <class _T1, class _T2>
 inline _LIBCPP_HIDE_FROM_ABI constexpr _T1&& get(pair<_T1, _T2>&& __p) _NOEXCEPT {
-  return __get_pair<0>::get(std::move(__p));
+  return std::forward<_T1&&>(__p.first);
 }
 
 template <class _T1, class _T2>
 inline _LIBCPP_HIDE_FROM_ABI constexpr _T1 const&& get(pair<_T1, _T2> const&& __p) _NOEXCEPT {
-  return __get_pair<0>::get(std::move(__p));
+  return std::forward<_T1 const&&>(__p.first);
 }
 
 template <class _T1, class _T2>
 inline _LIBCPP_HIDE_FROM_ABI constexpr _T1& get(pair<_T2, _T1>& __p) _NOEXCEPT {
-  return __get_pair<1>::get(__p);
+  return __p.second;
 }
----------------
ldionne wrote:

The way this was originally written is really confusing! `_T1` is sneakily used as the second template argument of `pair`, that's subtle. Could be refactored as a separate patch.

https://github.com/llvm/llvm-project/pull/114984