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llvm-project/libcxx/test/std/utilities/optional/optional.specalg/swap.pass.cpp

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Implement N4606 optional Summary: Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional. - Update relational operators per http://wg21.link/P0307 - Update to requirements of http://wg21.link/P0032 - Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable. Audit P/Rs for optional LWG issues: - 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R). - 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression. - 2740 "constexpr optional<T>::operator->" Already conforming. - 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented. - 2748 "swappable traits for optionals" Already conforming. - 2753 "Optional's constructors and assignments need constraints" Implemented. Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey! Reviewers: mclow.lists, CaseyCarter, EricWF Differential Revision: https://reviews.llvm.org/D22741 llvm-svn: 283980
2016-10-12 15:46:20 +08:00
//===----------------------------------------------------------------------===//
//
// 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
// <optional>
// template <class T> void swap(optional<T>& x, optional<T>& y)
// noexcept(noexcept(x.swap(y)));
#include <optional>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
#include "archetypes.hpp"
using std::optional;
class X
{
int i_;
public:
static unsigned dtor_called;
X(int i) : i_(i) {}
X(X&& x) = default;
X& operator=(X&&) = default;
~X() {++dtor_called;}
friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
};
unsigned X::dtor_called = 0;
class Y
{
int i_;
public:
static unsigned dtor_called;
Y(int i) : i_(i) {}
Y(Y&&) = default;
~Y() {++dtor_called;}
friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
friend void swap(Y& x, Y& y) {std::swap(x.i_, y.i_);}
};
unsigned Y::dtor_called = 0;
class Z
{
int i_;
public:
Z(int i) : i_(i) {}
Z(Z&&) { TEST_THROW(7);}
friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
friend void swap(Z& x, Z& y) { TEST_THROW(6);}
};
struct NonSwappable {
NonSwappable(NonSwappable const&) = delete;
};
void swap(NonSwappable&, NonSwappable&) = delete;
void test_swap_sfinae() {
using std::optional;
{
using T = TestTypes::TestType;
static_assert(std::is_swappable_v<optional<T>>, "");
}
{
using T = TestTypes::MoveOnly;
static_assert(std::is_swappable_v<optional<T>>, "");
}
{
using T = TestTypes::Copyable;
static_assert(std::is_swappable_v<optional<T>>, "");
}
{
using T = TestTypes::NoCtors;
static_assert(!std::is_swappable_v<optional<T>>, "");
}
{
using T = NonSwappable;
static_assert(!std::is_swappable_v<optional<T>>, "");
}
{
// Even thought CopyOnly has deleted move operations, those operations
// cause optional<CopyOnly> to have implicitly deleted move operations
// that decay into copies.
using T = TestTypes::CopyOnly;
using Opt = optional<T>;
T::reset();
Opt L(101), R(42);
T::reset_constructors();
std::swap(L, R);
assert(L->value == 42);
assert(R->value == 101);
assert(T::copy_constructed == 1);
assert(T::constructed == T::copy_constructed);
assert(T::assigned == 2);
assert(T::assigned == T::copy_assigned);
}
}
int main()
{
test_swap_sfinae();
{
optional<int> opt1;
optional<int> opt2;
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
}
{
optional<int> opt1(1);
optional<int> opt2;
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == false);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 1);
}
{
optional<int> opt1;
optional<int> opt2(2);
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 2);
assert(static_cast<bool>(opt2) == false);
}
{
optional<int> opt1(1);
optional<int> opt2(2);
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 2);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 1);
}
{
optional<X> opt1;
optional<X> opt2;
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
assert(X::dtor_called == 0);
}
{
optional<X> opt1(1);
optional<X> opt2;
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == false);
X::dtor_called = 0;
swap(opt1, opt2);
assert(X::dtor_called == 1);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 1);
}
{
optional<X> opt1;
optional<X> opt2(2);
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
X::dtor_called = 0;
swap(opt1, opt2);
assert(X::dtor_called == 1);
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 2);
assert(static_cast<bool>(opt2) == false);
}
{
optional<X> opt1(1);
optional<X> opt2(2);
static_assert(noexcept(swap(opt1, opt2)) == true, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
X::dtor_called = 0;
swap(opt1, opt2);
assert(X::dtor_called == 1); // from inside std::swap
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 2);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 1);
}
{
optional<Y> opt1;
optional<Y> opt2;
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
assert(Y::dtor_called == 0);
}
{
optional<Y> opt1(1);
optional<Y> opt2;
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == false);
Y::dtor_called = 0;
swap(opt1, opt2);
assert(Y::dtor_called == 1);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 1);
}
{
optional<Y> opt1;
optional<Y> opt2(2);
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
Y::dtor_called = 0;
swap(opt1, opt2);
assert(Y::dtor_called == 1);
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 2);
assert(static_cast<bool>(opt2) == false);
}
{
optional<Y> opt1(1);
optional<Y> opt2(2);
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
Y::dtor_called = 0;
swap(opt1, opt2);
assert(Y::dtor_called == 0);
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 2);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 1);
}
{
optional<Z> opt1;
optional<Z> opt2;
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
swap(opt1, opt2);
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == false);
}
#ifndef TEST_HAS_NO_EXCEPTIONS
{
optional<Z> opt1;
opt1.emplace(1);
optional<Z> opt2;
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == false);
try
{
swap(opt1, opt2);
assert(false);
}
catch (int i)
{
assert(i == 7);
}
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == false);
}
{
optional<Z> opt1;
optional<Z> opt2;
opt2.emplace(2);
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
try
{
swap(opt1, opt2);
assert(false);
}
catch (int i)
{
assert(i == 7);
}
assert(static_cast<bool>(opt1) == false);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
}
{
optional<Z> opt1;
opt1.emplace(1);
optional<Z> opt2;
opt2.emplace(2);
static_assert(noexcept(swap(opt1, opt2)) == false, "");
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
try
{
swap(opt1, opt2);
assert(false);
}
catch (int i)
{
assert(i == 6);
}
assert(static_cast<bool>(opt1) == true);
assert(*opt1 == 1);
assert(static_cast<bool>(opt2) == true);
assert(*opt2 == 2);
}
#endif // TEST_HAS_NO_EXCEPTIONS
}