mirror/example/meta_prog_11.cpp

This example shows the usage of the meta-programming utilities and the intrinsic meta-functions for various meta-objects

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>
#include <mirror/utils/quick_reg.hpp>
#include <type_traits>
#include <iostream>

bool x = false;
int y = 123;
double z = 456.789;

namespace test {

short w = 0;
bool x = true;
long y = 2345;
float z = 6.789;

} // namespace test

MIRROR_REG_BEGIN

MIRROR_QREG_GLOBAL_SCOPE_VARIABLES((x)(y)(z))

MIRROR_QREG_GLOBAL_SCOPE_NAMESPACE(test)
MIRROR_QREG_FREE_VARIABLES(test, (w)(x)(y)(z))

MIRROR_REG_END


MIRROR_NAMESPACE_BEGIN

// Helper functor class used by for_each_ii in print_free_variables_of
struct name_printer
{
    template <typename IterInfo>
    void operator()(IterInfo) const
    {
        typedef typename IterInfo::type MetaFreeVariable;
        // print the full name of the current member variable
        std::cout << MetaFreeVariable::full_name()
            << " = "
            << MetaFreeVariable::get();
        // if this is the last element in the traversal
        // then print the final dot or print a separating comma
        // otherwise
        if(IterInfo::is_last::value)
            std::cout << ".";
        else    std::cout << ", ";
    }
};

template <typename MetaNamespace>
void print_free_variables_of(void)
{
    using namespace mirror;
    std::cout << "Variables in the '"
        << MetaNamespace::full_name()
        << "' namespace: ";
    mp::for_each_ii<
        mp::only_if<
            members<MetaNamespace>,
            mirror::mp::is_a<
                mp::arg<1>,
                meta_free_variable_tag
            >
        >
    >(name_printer());
    std::cout << std::endl;
}


MIRROR_NAMESPACE_END


int main(void)
{
    using namespace mirror;
    print_free_variables_of<
        MIRRORED_GLOBAL_SCOPE()
    >();
    print_free_variables_of<
        MIRRORED_NAMESPACE(test)
    >();
    //
    return 0;
}

/* Example of output:
Variables in the '' namespace: x = 0, y = 123, z = 456.789.
Variables in the 'test' namespace: test::w = 0, test::x = 1, test::y = 2345, test::z = 6.789.
*/