From b4e7013794972ddfcaf042a775b06c94d20ba96b Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Fri, 3 Jan 2020 14:44:39 +0000 Subject: [PATCH] libstdc++: Only use std::compare_three_way when concepts are supported Clang now supports three-way comparisons. That causes both overloads of std::lexicographical_compare_three_way to be defined, but the second one uses std::compare_three_way which depends on concepts. Clang does not yet support concepts, so the second overload should also depend on __cpp_lib_concepts. * include/bits/stl_algobase.h (lexicographical_compare_three_way): Only define four-argument overload when __cpp_lib_concepts is defined. From-SVN: r279861 --- libstdc++-v3/ChangeLog | 5 +++++ libstdc++-v3/include/bits/stl_algobase.h | 2 ++ 2 files changed, 7 insertions(+) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index bb32f6e..3b65de7 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,8 @@ +2020-01-03 Jonathan Wakely + + * include/bits/stl_algobase.h (lexicographical_compare_three_way): + Only define four-argument overload when __cpp_lib_concepts is defined. + 2020-01-01 John David Anglin * config/abi/post/hppa-linux-gnu/baseline_symbols.txt: Update. diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h index 13de6ae..76c323a 100644 --- a/libstdc++-v3/include/bits/stl_algobase.h +++ b/libstdc++-v3/include/bits/stl_algobase.h @@ -1751,6 +1751,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO : __first2 != __last2 ? strong_ordering::less : strong_ordering::equal; } +#if __cpp_lib_concepts template constexpr auto lexicographical_compare_three_way(_InputIter1 __first1, @@ -1762,6 +1763,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO __first2, __last2, compare_three_way{}); } +#endif // concepts #endif // three_way_comparison template