test_object.cpp

#include "test_object.h"
#include <gtest/gtest.h>

namespace
{
    int transcode(int data, void const* ptr)
    {
        return data ^ static_cast<int>(reinterpret_cast<std::ptrdiff_t>(ptr) / sizeof(test_object));
    }
}

test_object::test_object(int data)
    : data(transcode(data, this))
{
    auto p = instances.insert(this);
    EXPECT_TRUE(p.second);
}

test_object::test_object(test_object const& other)
{
    {
        EXPECT_TRUE(instances.find(&other) != instances.end());
        auto p = instances.insert(this);
        EXPECT_TRUE(p.second);
    }
    data = transcode(transcode(other.data, &other), this);
}

test_object::~test_object()
{
    size_t n = instances.erase(this);
    EXPECT_EQ(1u, n);
}

test_object& test_object::operator=(test_object const& c)
{
    EXPECT_TRUE(instances.find(this) != instances.end());
    data = transcode(transcode(c.data, &c), this);
    return *this;
}

test_object::operator int() const
{
    EXPECT_TRUE(instances.find(this) != instances.end());

    return transcode(data, this);
}

std::set<test_object const*> test_object::instances;

test_object::no_new_instances_guard::no_new_instances_guard()
    : old_instances(instances)
{}

test_object::no_new_instances_guard::~no_new_instances_guard()
{
    EXPECT_TRUE(old_instances == instances);
}

void test_object::no_new_instances_guard::expect_no_instances() const
{
    EXPECT_TRUE(old_instances == instances);
}