[libcxx-commits] [PATCH] D144262: [libc++][ranges] Implement LWG-3865 Sorting a range of pairs

[Mark de Wever via Phabricator via libcxx-commits]

Mordante added subscribers: strega-nil, ldionne, Mordante.
Mordante added a comment.

Thanks for your patch! I haven't looked in detail, since I first like to agree to which language versions we want to backport this fix.



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Comment at: libcxx/test/std/utilities/tuple/tuple.tuple/tuple.apply/make_from_tuple.pass.cpp:68
-    return lhs.first == rhs.first && lhs.second == rhs.second;
-}
-
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We typically back-port LWG issues to older language versions.
However I'm a bit wary of retroactively applying this LWG issue, since it may affect existing code.
Looking at MSVC STL it seems @strega-nil has the same concerns.
https://github.com/microsoft/STL/pull/3476/files/4f2ec495a6b5e6ab61d504663b0ad7d3db9db547#r1110452521

Since `operator==` and `operator<=>` are added/changed in C++20, I feel less wary to change it there.
Doing this back to C++03 feels a bit scary.

@ldionne What's your opinion?




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Comment at: libcxx/test/std/utilities/utility/pairs/pairs.spec/comparison.pass.cpp:11
 
 // template <class T1, class T2> struct pair
 
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Can you also update `libcxx/test/std/utilities/utility/pairs/pairs.spec/three_way_comparison.pass.cpp`.


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