turtle/doc/example/patterns_invoke_functor.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)

// Intentionally duplicate to have complete examples and minimal user visible, yet tested test code
#include <boost/test/unit_test.hpp>

static void someFunctor(int newValue);
//[ invoke_functor_problem
#include <functional>

    class base_class
    {
    public:
        virtual void method( const std::function< void( int ) >& functor ) = 0;
    };

    // the function will call 'method' with a functor to be applied
    void function(base_class& c) { c.method(someFunctor); } 
//]

// Some test-only code to verify what is described
static int receivedValue = 0;
static void someFunctor(int newValue)
{
    receivedValue = newValue;
}
// Check that the functor was called with 42
struct CheckReceivedValue
{
    void teardown()
    {
        BOOST_CHECK(receivedValue == 42); // functor was called and received the value 42
    }
};
// And force using it w/o showing that in the docs
#undef BOOST_AUTO_TEST_CASE
#define BOOST_AUTO_TEST_CASE(name) BOOST_FIXTURE_TEST_CASE(name, CheckReceivedValue)

//[ invoke_functor_solution
#include <boost/test/unit_test.hpp>
#include <turtle/mock.hpp>

namespace
{
    MOCK_BASE_CLASS( mock_class, base_class )
    {
        MOCK_METHOD( method, 1 )
    };
}

BOOST_AUTO_TEST_CASE( how_to_invoke_a_functor_passed_as_parameter_of_a_mock_method )
{
    mock_class mock;
    MOCK_EXPECT( mock.method ).calls( [](const auto &functor){ functor(42); } ); // whenever 'method' is called, invoke the functor with 42
    function( mock );
}
//]