//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <tuple>
// template <class... Types> class tuple;
// template <class... UTypes>
// tuple& operator=(const tuple<UTypes...>& u);
// UNSUPPORTED: c++03
#include <tuple>
#include <string>
#include <cassert>
#include "test_macros.h"
struct B {
int id_;
constexpr explicit B(int i = 0) : id_(i) {}
};
struct D : B {
constexpr explicit D(int i = 0) : B(i) {}
};
struct NonAssignable {
NonAssignable& operator=(NonAssignable const&) = delete;
NonAssignable& operator=(NonAssignable&&) = delete;
};
struct NothrowCopyAssignable {
NothrowCopyAssignable(NothrowCopyAssignable const&) = delete;
NothrowCopyAssignable& operator=(NothrowCopyAssignable const&) noexcept { return *this; }
};
struct PotentiallyThrowingCopyAssignable {
PotentiallyThrowingCopyAssignable(PotentiallyThrowingCopyAssignable const&) = delete;
PotentiallyThrowingCopyAssignable& operator=(PotentiallyThrowingCopyAssignable const&) { return *this; }
};
TEST_CONSTEXPR_CXX20
bool test()
{
{
typedef std::tuple<long> T0;
typedef std::tuple<long long> T1;
T0 t0(2);
T1 t1;
t1 = t0;
assert(std::get<0>(t1) == 2);
}
{
typedef std::tuple<long, char> T0;
typedef std::tuple<long long, int> T1;
T0 t0(2, 'a');
T1 t1;
t1 = t0;
assert(std::get<0>(t1) == 2);
assert(std::get<1>(t1) == int('a'));
}
{
typedef std::tuple<long, char, D> T0;
typedef std::tuple<long long, int, B> T1;
T0 t0(2, 'a', D(3));
T1 t1;
t1 = t0;
assert(std::get<0>(t1) == 2);
assert(std::get<1>(t1) == int('a'));
assert(std::get<2>(t1).id_ == 3);
}
{
D d(3);
D d2(2);
typedef std::tuple<long, char, D&> T0;
typedef std::tuple<long long, int, B&> T1;
T0 t0(2, 'a', d2);
T1 t1(1, 'b', d);
t1 = t0;
assert(std::get<0>(t1) == 2);
assert(std::get<1>(t1) == int('a'));
assert(std::get<2>(t1).id_ == 2);
}
{
// Test that tuple evaluates correctly applies an lvalue reference
// before evaluating is_assignable (i.e. 'is_assignable<int&, int&>')
// instead of evaluating 'is_assignable<int&&, int&>' which is false.
int x = 42;
int y = 43;
std::tuple<int&&> t(std::move(x));
std::tuple<int&> t2(y);
t = t2;
assert(std::get<0>(t) == 43);
assert(&std::get<0>(t) == &x);
}
return true;
}
int main(int, char**)
{
test();
#if TEST_STD_VER >= 20
static_assert(test());
#endif
{
using T = std::tuple<int, NonAssignable>;
using U = std::tuple<NonAssignable, int>;
static_assert(!std::is_assignable<T&, U const&>::value, "");
static_assert(!std::is_assignable<U&, T const&>::value, "");
}
{
typedef std::tuple<NothrowCopyAssignable, long> T0;
typedef std::tuple<NothrowCopyAssignable, int> T1;
static_assert(std::is_nothrow_assignable<T0&, T1 const&>::value, "");
}
{
typedef std::tuple<PotentiallyThrowingCopyAssignable, long> T0;
typedef std::tuple<PotentiallyThrowingCopyAssignable, int> T1;
static_assert(std::is_assignable<T0&, T1 const&>::value, "");
static_assert(!std::is_nothrow_assignable<T0&, T1 const&>::value, "");
}
return 0;
}