rubber/example/free_variables.cpp

This example shows the usage of the type erasures for compile-time Mirror's meta-object with the for-each algorithm and lambda functions

Copyright 2008-2011 Matus Chochlik. 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)

#include <mirror/mirror.hpp>

#define RUBBER_META_TYPE_OPERATIONS write_to_cout
#include <rubber/operation/write_to_ostream.hpp>

#include <rubber/rubber.hpp>
#include <iostream>
#include <vector>

// Total count of instances of test ever created
unsigned total_count = 0;
// Count of instances of test currently in existence
unsigned alive_count = 0;

struct test
{
    test(void)
    {
        ++total_count;
        ++alive_count;
    }

    test(const test&)
    {
        ++total_count;
        ++alive_count;
    }

    ~test(void)
    {
        --alive_count;
    }
};

MIRROR_REG_BEGIN

MIRROR_REG_GLOBAL_SCOPE_VARIABLE(_, total_count)
MIRROR_REG_GLOBAL_SCOPE_VARIABLE(_, alive_count)

MIRROR_REG_END

void print_stats(int tag)
{
    using namespace rubber;
    std::cout << "Checkpoint " << tag << std::endl;
    std::cout << "--------------" << std::endl;
    mirror::mp::for_each<
        mirror::free_variables<
            MIRRORED_GLOBAL_SCOPE()
        >
    >(
        [](const meta_free_variable& var)
        {
            std::cout << var.base_name() << " = ";
            var.type().examine_by<write_to_cout>(var.get());
            std::cout << std::endl;
        }
    );
    std::cout << "--------------" << std::endl;
}

int main(void)
{
    int tag = 0;
    //
    print_stats(++tag);
    std::vector<test> v;
    print_stats(++tag);
    {
        std::vector<test> v1(10);
        print_stats(++tag);
        std::vector<test> v2(10);
        print_stats(++tag);
        std::vector<test> v3(10);
        print_stats(++tag);
        v.swap(v1);
        print_stats(++tag);
        v.insert(v.end(), v2.begin(), v2.end());
        print_stats(++tag);
        v.insert(v.begin(), v3.begin(), v3.end());
        print_stats(++tag);
    }
    print_stats(++tag);
    v.clear();
    print_stats(++tag);
    return 0;
}

/* Example of output:
Checkpoint 1
--------------
total_count = 0
alive_count = 0
--------------
Checkpoint 2
--------------
total_count = 0
alive_count = 0
--------------
Checkpoint 3
--------------
total_count = 10
alive_count = 10
--------------
Checkpoint 4
--------------
total_count = 20
alive_count = 20
--------------
Checkpoint 5
--------------
total_count = 30
alive_count = 30
--------------
Checkpoint 6
--------------
total_count = 30
alive_count = 30
--------------
Checkpoint 7
--------------
total_count = 50
alive_count = 40
--------------
Checkpoint 8
--------------
total_count = 80
alive_count = 50
--------------
Checkpoint 9
--------------
total_count = 80
alive_count = 30
--------------
Checkpoint 10
--------------
total_count = 80
alive_count = 0
--------------
*/