forked from OSchip/llvm-project
Workaround GCC bug PR78489 - SFINAE order is not respected.
This patch works around variant test failures which are new to GCC 8. GCC 8 either doesn't perform SFINAE in lexical order, or it doesn't halt after encountering the first failure. This causes hard error to occur instead of substitution failure. See gcc.gnu.org/PR78489 llvm-svn: 328261
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@ -1156,29 +1156,24 @@ public:
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: __impl(in_place_index<_Ip>, _VSTD::forward<_Arg>(__arg)) {}
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template <size_t _Ip, class... _Args,
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class = enable_if_t<(_Ip < sizeof...(_Types)), int>,
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class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
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enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
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enable_if_t<(_Ip < sizeof...(_Types)), size_t> _Ip2 = _Ip,
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class _Tp = variant_alternative_t<_Ip2, variant<_Types...>>,
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enable_if_t<is_constructible<_Tp, _Args...>::value, int> = 0>
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inline _LIBCPP_INLINE_VISIBILITY
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explicit constexpr variant(
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in_place_index_t<_Ip>,
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_Args&&... __args) noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
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explicit constexpr variant(in_place_index_t<_Ip>,
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_Args&&... __args)
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noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
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: __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
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template <
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size_t _Ip,
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class _Up,
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class... _Args,
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enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
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class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
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template <size_t _Ip, class _Up, class... _Args,
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enable_if_t<(_Ip < sizeof...(_Types)), size_t> _Ip2 = _Ip,
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class _Tp = variant_alternative_t<_Ip2, variant<_Types...>>,
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enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
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int> = 0>
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inline _LIBCPP_INLINE_VISIBILITY
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explicit constexpr variant(
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in_place_index_t<_Ip>,
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initializer_list<_Up> __il,
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_Args&&... __args) noexcept(
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is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>)
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explicit constexpr variant(in_place_index_t<_Ip>, initializer_list<_Up> __il,
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_Args&&... __args)
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noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>)
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: __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
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template <
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@ -73,6 +73,12 @@ void test_ctor_sfinae() {
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!std::is_constructible<V, std::in_place_index_t<2>, IL>::value, "");
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static_assert(!test_convertible<V, std::in_place_index_t<2>, IL>(), "");
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}
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{ // index not in variant
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using V = std::variant<InitList, InitListArg, int>;
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static_assert(
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!std::is_constructible<V, std::in_place_index_t<3>, IL>::value, "");
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static_assert(!test_convertible<V, std::in_place_index_t<3>, IL>(), "");
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}
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}
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void test_ctor_basic() {
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