diff --git a/include/tuple b/include/tuple index aa4713faf..a52b934aa 100644 --- a/include/tuple +++ b/include/tuple @@ -929,6 +929,16 @@ public: void swap(tuple&) _NOEXCEPT {} }; +#ifdef __cpp_deduction_guides +// NOTE: These are not yet standardized, but are required to simulate the +// implicit deduction guide that should be generated had libc++ declared the +// tuple-like constructors "correctly" +template +tuple(allocator_arg_t, const _Alloc&, tuple<_Args...> const&) -> tuple<_Args...>; +template +tuple(allocator_arg_t, const _Alloc&, tuple<_Args...>&&) -> tuple<_Args...>; +#endif + template inline _LIBCPP_INLINE_VISIBILITY typename enable_if diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/implicit_deduction_guides.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/implicit_deduction_guides.pass.cpp new file mode 100644 index 000000000..dba17ce29 --- /dev/null +++ b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/implicit_deduction_guides.pass.cpp @@ -0,0 +1,150 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// UNSUPPORTED: c++98, c++03, c++11, c++14 +// UNSUPPORTED: libcpp-no-deduction-guides + +// + +// Test that the constructors offered by std::basic_string are formulated +// so they're compatible with implicit deduction guides. + +#include +#include +#include + +#include "test_macros.h" +#include "archetypes.hpp" + + +// Overloads +// using A = Allocator +// using AT = std::allocator_arg_t +// --------------- +// (1) tuple(const Types&...) -> tuple +// (2) explicit tuple(const Types&...) -> tuple +// (3) tuple(AT, A const&, Types const&...) -> tuple +// (4) explicit tuple(AT, A const&, Types const&...) -> tuple +// (5) tuple(tuple const& t) -> decltype(t) +// (6) tuple(tuple&& t) -> decltype(t) +// (7) tuple(AT, A const&, tuple const& t) -> decltype(t) +// (8) tuple(AT, A const&, tuple&& t) -> decltype(t) +void test_primary_template() +{ + const std::allocator A; + const auto AT = std::allocator_arg; + { // Testing (1) + int x = 101; + std::tuple t1(42); + ASSERT_SAME_TYPE(decltype(t1), std::tuple); + std::tuple t2(x, 0.0, nullptr); + ASSERT_SAME_TYPE(decltype(t2), std::tuple); + } + { // Testing (2) + using T = ExplicitTestTypes::TestType; + static_assert(!std::is_convertible::value, ""); + + std::tuple t1(T{}); + ASSERT_SAME_TYPE(decltype(t1), std::tuple); + + const T v{}; + std::tuple t2(T{}, 101l, v); + ASSERT_SAME_TYPE(decltype(t2), std::tuple); + } + { // Testing (3) + int x = 101; + std::tuple t1(AT, A, 42); + ASSERT_SAME_TYPE(decltype(t1), std::tuple); + + std::tuple t2(AT, A, 42, 0.0, x); + ASSERT_SAME_TYPE(decltype(t2), std::tuple); + } + { // Testing (4) + using T = ExplicitTestTypes::TestType; + static_assert(!std::is_convertible::value, ""); + + std::tuple t1(AT, A, T{}); + ASSERT_SAME_TYPE(decltype(t1), std::tuple); + + const T v{}; + std::tuple t2(AT, A, T{}, 101l, v); + ASSERT_SAME_TYPE(decltype(t2), std::tuple); + } + { // Testing (5) + using Tup = std::tuple; + const Tup t(42, nullptr); + + std::tuple t1(t); + ASSERT_SAME_TYPE(decltype(t1), Tup); + } + { // Testing (6) + using Tup = std::tuple; + std::tuple t1(Tup(nullptr, 42, 'a')); + ASSERT_SAME_TYPE(decltype(t1), Tup); + } + { // Testing (7) + using Tup = std::tuple; + const Tup t(42, nullptr); + + std::tuple t1(AT, A, t); + ASSERT_SAME_TYPE(decltype(t1), Tup); + } + { // Testing (8) + using Tup = std::tuple; + std::tuple t1(AT, A, Tup(nullptr, 42, 'a')); + ASSERT_SAME_TYPE(decltype(t1), Tup); + } +} + +// Overloads +// using A = Allocator +// using AT = std::allocator_arg_t +// --------------- +// (1) tuple() -> tuple<> +// (2) tuple(AT, A const&) -> tuple<> +// (3) tuple(tuple const&) -> tuple<> +// (4) tuple(tuple&&) -> tuple<> +// (5) tuple(AT, A const&, tuple const&) -> tuple<> +// (6) tuple(AT, A const&, tuple&&) -> tuple<> +void test_empty_specialization() +{ + std::allocator A; + const auto AT = std::allocator_arg; + { // Testing (1) + std::tuple t1{}; + ASSERT_SAME_TYPE(decltype(t1), std::tuple<>); + } + { // Testing (2) + std::tuple t1{AT, A}; + ASSERT_SAME_TYPE(decltype(t1), std::tuple<>); + } + { // Testing (3) + const std::tuple<> t{}; + std::tuple t1(t); + ASSERT_SAME_TYPE(decltype(t1), std::tuple<>); + } + { // Testing (4) + std::tuple t1(std::tuple<>{}); + ASSERT_SAME_TYPE(decltype(t1), std::tuple<>); + } + { // Testing (5) + const std::tuple<> t{}; + std::tuple t1(AT, A, t); + ASSERT_SAME_TYPE(decltype(t1), std::tuple<>); + } + { // Testing (6) + std::tuple t1(AT, A, std::tuple<>{}); + ASSERT_SAME_TYPE(decltype(t1), std::tuple<>); + } +} + +int main() { + test_primary_template(); + test_empty_specialization(); +}