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// MPark.Variant
//
// Copyright Michael Park, 2015-2017
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <mpark/variant.hpp>
#include <string>
#include <gtest/gtest.h>
#include "util.hpp"
TEST(Swap, Same) {
mpark::variant<int, std::string> v("hello");
mpark::variant<int, std::string> w("world");
// Check `v`.
EXPECT_EQ("hello", mpark::get<std::string>(v));
// Check `w`.
EXPECT_EQ("world", mpark::get<std::string>(w));
// Swap.
using std::swap;
swap(v, w);
// Check `v`.
EXPECT_EQ("world", mpark::get<std::string>(v));
// Check `w`.
EXPECT_EQ("hello", mpark::get<std::string>(w));
}
TEST(Swap, Different) {
mpark::variant<int, std::string> v(42);
mpark::variant<int, std::string> w("hello");
// Check `v`.
EXPECT_EQ(42, mpark::get<int>(v));
// Check `w`.
EXPECT_EQ("hello", mpark::get<std::string>(w));
// Swap.
using std::swap;
swap(v, w);
// Check `v`.
EXPECT_EQ("hello", mpark::get<std::string>(v));
// Check `w`.
EXPECT_EQ(42, mpark::get<int>(w));
}
#ifdef MPARK_EXCEPTIONS
TEST(Swap, OneValuelessByException) {
// `v` normal, `w` corrupted.
mpark::variant<int, move_thrower_t> v(42), w(42);
EXPECT_THROW(w = move_thrower_t{}, MoveConstruction);
EXPECT_EQ(42, mpark::get<int>(v));
EXPECT_TRUE(w.valueless_by_exception());
// Swap.
using std::swap;
swap(v, w);
// Check `v`, `w`.
EXPECT_TRUE(v.valueless_by_exception());
EXPECT_EQ(42, mpark::get<int>(w));
}
TEST(Swap, BothValuelessByException) {
// `v`, `w` both corrupted.
mpark::variant<int, move_thrower_t> v(42);
EXPECT_THROW(v = move_thrower_t{}, MoveConstruction);
mpark::variant<int, move_thrower_t> w(v);
EXPECT_TRUE(v.valueless_by_exception());
EXPECT_TRUE(w.valueless_by_exception());
// Swap.
using std::swap;
swap(v, w);
// Check `v`, `w`.
EXPECT_TRUE(v.valueless_by_exception());
EXPECT_TRUE(w.valueless_by_exception());
}
#endif
TEST(Swap, DtorsSame) {
struct Obj {
Obj(size_t *dtor_count) : dtor_count_(dtor_count) {}
Obj(const Obj &) = default;
Obj(Obj &&) = default;
~Obj() { ++(*dtor_count_); }
Obj &operator=(const Obj &) = default;
Obj &operator=(Obj &&) = default;
size_t *dtor_count_;
}; // Obj
size_t v_count = 0;
size_t w_count = 0;
{
mpark::variant<Obj> v{&v_count}, w{&w_count};
using std::swap;
swap(v, w);
// Calls `std::swap(Obj &lhs, Obj &rhs)`, with which we perform:
// ```
// {
// Obj temp(move(lhs));
// lhs = move(rhs);
// rhs = move(temp);
// } `++v_count` from `temp::~Obj()`.
// ```
EXPECT_EQ(1u, v_count);
EXPECT_EQ(0u, w_count);
}
EXPECT_EQ(2u, v_count);
EXPECT_EQ(1u, w_count);
}
namespace detail {
struct Obj {
Obj(size_t *dtor_count) : dtor_count_(dtor_count) {}
Obj(const Obj &) = default;
Obj(Obj &&) = default;
~Obj() { ++(*dtor_count_); }
Obj &operator=(const Obj &) = default;
Obj &operator=(Obj &&) = default;
size_t *dtor_count_;
}; // Obj
static void swap(Obj &lhs, Obj &rhs) noexcept {
std::swap(lhs.dtor_count_, rhs.dtor_count_);
}
} // namespace detail
TEST(Swap, DtorsSameWithSwap) {
size_t v_count = 0;
size_t w_count = 0;
{
mpark::variant<detail::Obj> v{&v_count}, w{&w_count};
using std::swap;
swap(v, w);
// Calls `detail::swap(Obj &lhs, Obj &rhs)`, with which doesn't call any destructors.
EXPECT_EQ(0u, v_count);
EXPECT_EQ(0u, w_count);
}
EXPECT_EQ(1u, v_count);
EXPECT_EQ(1u, w_count);
}
TEST(Swap, DtorsDifferent) {
struct V {
V(size_t *dtor_count) : dtor_count_(dtor_count) {}
V(const V &) = default;
V(V &&) = default;
~V() { ++(*dtor_count_); }
V &operator=(const V &) = default;
V &operator=(V &&) = default;
size_t *dtor_count_;
}; // V
struct W {
W(size_t *dtor_count) : dtor_count_(dtor_count) {}
W(const W &) = default;
W(W &&) = default;
~W() { ++(*dtor_count_); }
W &operator=(const W &) = default;
W &operator=(W &&) = default;
size_t *dtor_count_;
}; // W
size_t v_count = 0;
size_t w_count = 0;
{
mpark::variant<V, W> v{mpark::in_place_type_t<V>{}, &v_count};
mpark::variant<V, W> w{mpark::in_place_type_t<W>{}, &w_count};
using std::swap;
swap(v, w);
EXPECT_EQ(1u, v_count);
EXPECT_EQ(2u, w_count);
}
EXPECT_EQ(2u, v_count);
EXPECT_EQ(3u, w_count);
}
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