118 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// <tuple>10 11// template <class... Types> class tuple;12 13// explicit(see-below) constexpr tuple();14 15// UNSUPPORTED: c++0316 17#include <tuple>18#include <string>19#include <cassert>20#include <type_traits>21 22#include "test_macros.h"23#include "DefaultOnly.h"24 25struct NoDefault {26 NoDefault() = delete;27 explicit NoDefault(int) { }28};29 30struct NoExceptDefault {31 NoExceptDefault() noexcept = default;32};33 34struct ThrowingDefault {35 ThrowingDefault() { }36};37 38struct IllFormedDefault {39 IllFormedDefault(int x) : value(x) {}40 template <bool Pred = false>41 constexpr IllFormedDefault() {42 static_assert(Pred,43 "The default constructor should not be instantiated");44 }45 int value;46};47 48int main(int, char**)49{50 {51 std::tuple<> t;52 (void)t;53 }54 {55 std::tuple<int> t;56 assert(std::get<0>(t) == 0);57 }58 {59 std::tuple<int, char*> t;60 assert(std::get<0>(t) == 0);61 assert(std::get<1>(t) == nullptr);62 }63 {64 std::tuple<int, char*, std::string> t;65 assert(std::get<0>(t) == 0);66 assert(std::get<1>(t) == nullptr);67 assert(std::get<2>(t) == "");68 }69 {70 std::tuple<int, char*, std::string, DefaultOnly> t;71 assert(std::get<0>(t) == 0);72 assert(std::get<1>(t) == nullptr);73 assert(std::get<2>(t) == "");74 assert(std::get<3>(t) == DefaultOnly());75 }76 {77 // See bug #21157.78 static_assert(!std::is_default_constructible<std::tuple<NoDefault>>(), "");79 static_assert(!std::is_default_constructible<std::tuple<DefaultOnly, NoDefault>>(), "");80 static_assert(!std::is_default_constructible<std::tuple<NoDefault, DefaultOnly, NoDefault>>(), "");81 }82 {83 static_assert(noexcept(std::tuple<NoExceptDefault>()), "");84 static_assert(noexcept(std::tuple<NoExceptDefault, NoExceptDefault>()), "");85 86 static_assert(!noexcept(std::tuple<ThrowingDefault, NoExceptDefault>()), "");87 static_assert(!noexcept(std::tuple<NoExceptDefault, ThrowingDefault>()), "");88 static_assert(!noexcept(std::tuple<ThrowingDefault, ThrowingDefault>()), "");89 }90 {91 constexpr std::tuple<> t;92 (void)t;93 }94 {95 constexpr std::tuple<int> t;96 assert(std::get<0>(t) == 0);97 }98 {99 constexpr std::tuple<int, char*> t;100 assert(std::get<0>(t) == 0);101 assert(std::get<1>(t) == nullptr);102 }103 {104 // Check that the SFINAE on the default constructor is not evaluated when105 // it isn't needed. If the default constructor is evaluated then this test106 // should fail to compile.107 IllFormedDefault v(0);108 std::tuple<IllFormedDefault> t(v);109 }110 {111 struct Base { };112 struct Derived : Base { protected: Derived() = default; };113 static_assert(!std::is_default_constructible<std::tuple<Derived, int> >::value, "");114 }115 116 return 0;117}118