catch2/tests/SelfTest/IntrospectiveTests/UniquePtr.tests.cpp

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// Copyright Catch2 Authors
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// https://www.boost.org/LICENSE_1_0.txt)
// SPDX-License-Identifier: BSL-1.0
#include <catch2/catch_test_macros.hpp>
#include <catch2/internal/catch_unique_ptr.hpp>
#include <tuple>
namespace {
struct unique_ptr_test_helper {
bool dummy = false;
};
} // end unnamed namespace
TEST_CASE("unique_ptr reimplementation: basic functionality", "[internals][unique-ptr]") {
using Catch::Detail::unique_ptr;
SECTION("Default constructed unique_ptr is empty") {
unique_ptr<int> ptr;
REQUIRE_FALSE(ptr);
REQUIRE(ptr.get() == nullptr);
}
SECTION("Take ownership of allocation") {
auto naked_ptr = new int{ 0 };
unique_ptr<int> ptr(naked_ptr);
REQUIRE(ptr);
REQUIRE(*ptr == 0);
REQUIRE(ptr.get() == naked_ptr);
SECTION("Plain reset deallocates") {
ptr.reset(); // this makes naked_ptr dangling!
REQUIRE_FALSE(ptr);
REQUIRE(ptr.get() == nullptr);
}
SECTION("Reset replaces ownership") {
ptr.reset(new int{ 2 });
REQUIRE(ptr);
REQUIRE(ptr.get() != nullptr);
REQUIRE(*ptr == 2);
}
}
SECTION("Release releases ownership") {
auto naked_ptr = new int{ 1 };
unique_ptr<int> ptr(naked_ptr);
ptr.release();
CHECK_FALSE(ptr);
CHECK(ptr.get() == nullptr);
delete naked_ptr;
}
SECTION("Move constructor") {
unique_ptr<int> ptr1(new int{ 1 });
auto ptr2(std::move(ptr1));
REQUIRE_FALSE(ptr1);
REQUIRE(ptr2);
REQUIRE(*ptr2 == 1);
}
SECTION("Move assignment") {
unique_ptr<int> ptr1(new int{ 1 }), ptr2(new int{ 2 });
ptr1 = std::move(ptr2);
REQUIRE_FALSE(ptr2);
REQUIRE(ptr1);
REQUIRE(*ptr1 == 2);
}
SECTION("free swap") {
unique_ptr<int> ptr1(new int{ 1 }), ptr2(new int{ 2 });
swap(ptr1, ptr2);
REQUIRE(*ptr1 == 2);
REQUIRE(*ptr2 == 1);
}
}
namespace {
struct base {
int i;
base(int i_) :i(i_) {}
};
struct derived : base { using base::base; };
struct unrelated {};
} // end unnamed namespace
static_assert( std::is_constructible<Catch::Detail::unique_ptr<base>,
Catch::Detail::unique_ptr<derived>>::value, "Upcasting is supported");
static_assert(!std::is_constructible<Catch::Detail::unique_ptr<derived>,
Catch::Detail::unique_ptr<base>>::value, "Downcasting is not supported");
static_assert(!std::is_constructible<Catch::Detail::unique_ptr<base>,
Catch::Detail::unique_ptr<unrelated>>::value, "Cannot just convert one ptr type to another");
TEST_CASE("Upcasting special member functions", "[internals][unique-ptr]") {
using Catch::Detail::unique_ptr;
unique_ptr<derived> dptr(new derived{3});
SECTION("Move constructor") {
unique_ptr<base> bptr(std::move(dptr));
REQUIRE(bptr->i == 3);
}
SECTION("move assignment") {
unique_ptr<base> bptr(new base{ 1 });
bptr = std::move(dptr);
REQUIRE(bptr->i == 3);
}
}
namespace {
struct move_detector {
bool has_moved = false;
move_detector() = default;
move_detector(move_detector const& rhs) = default;
move_detector& operator=(move_detector const& rhs) = default;
move_detector(move_detector&& rhs) noexcept {
rhs.has_moved = true;
}
move_detector& operator=(move_detector&& rhs) noexcept {
rhs.has_moved = true;
return *this;
}
};
} // end unnamed namespace
TEST_CASE("make_unique reimplementation", "[internals][unique-ptr]") {
using Catch::Detail::make_unique;
SECTION("From lvalue copies") {
move_detector lval;
auto ptr = make_unique<move_detector>(lval);
REQUIRE_FALSE(lval.has_moved);
}
SECTION("From rvalue moves") {
move_detector rval;
auto ptr = make_unique<move_detector>(std::move(rval));
REQUIRE(rval.has_moved);
}
SECTION("Variadic constructor") {
auto ptr = make_unique<std::tuple<int, double, int>>(1, 2., 3);
REQUIRE(*ptr == std::tuple<int, double, int>{1, 2., 3});
}
}