turtle/doc/example/patterns_quick_constraint.cpp

// http://turtle.sourceforge.net
//
// Copyright Mathieu Champlon 2014
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

//[ quick_constraint_problem
#define BOOST_AUTO_TEST_MAIN
#include <turtle/mock.hpp>
#include <boost/test/auto_unit_test.hpp>
#include <iostream>

namespace {
class my_class
{
public:
    explicit my_class(int data) : data_(data) {}
    int data_;
};

std::ostream& operator<<(std::ostream& os, const my_class& c) // my_class is serializable to an std::ostream
{
    return os << "my_class( " << c.data_ << " )";
}

MOCK_CLASS(my_mock){
    MOCK_METHOD(method, 1, void(const my_class&)) // how to simply write a custom constraint ?
};
} // namespace
//]

//[ quick_constraint_solution
#include <boost/lexical_cast.hpp>

namespace // in the same namespace as 'my_class'
{
bool operator==(const my_class& actual,
                const std::string& expected) // the first part of the trick is to compare to a string
{
    return boost::lexical_cast<std::string>(actual) == expected;
}
} // namespace

BOOST_AUTO_TEST_CASE(method_is_called)
{
    my_mock mock;
    MOCK_EXPECT(mock.method)
      .once()
      .with("my_class( 42 )"); // the second part of the trick is to express the constraint as a string
    mock.method(my_class(42));
}
//]