mirror/example/meta_prog_05.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 <iostream>

MIRROR_NAMESPACE_BEGIN

// Helper functor clas used by for_each_ii in print_integral_types_in
struct name_printer
{
    template <typename IterInfo>
    void operator()(IterInfo) const
    {
        typedef typename IterInfo::type MetaObject;
        // print the full name of the current element
        std::cout << MetaObject::full_name();
        // 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_integral_types_in(void)
{
    using namespace mirror;
    std::cout << "Integers in the '"
        << MetaNamespace::full_name()
        << "' namespace: ";
    // get the members of the passed MetaNamespace, filter only
    // the meta_types and then filter only those that reflect
    // integral types and finally for each of such meta-types
    // execute the name_printer functor
    mp::for_each_ii<
        mp::only_if<
            mp::only_if<
                members<MetaNamespace>,
                mp::is_a<
                    mp::arg<1>,
                    meta_type_tag
                >
            >,
            std::is_integral<
                original_type<
                    mp::arg<1>
                >
            >
        >
    >(name_printer());
    std::cout << std::endl;
}


MIRROR_NAMESPACE_END


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

/* Example of output:
Integers in the '' namespace: bool, char, unsigned char, wchar_t, short int, int, long int, unsigned short int, unsigned int, unsigned long int.
Integers in the 'std' namespace:
*/