lagoon/example/factories/physical_units.cpp

This example shows how to use a factory created by the factory generator with a script parsing plugin to generically construct instances of classes with non default constructors, from input strings.

Copyright 2006-2011 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)

//
// We want to use Lagoon's polymorphic factories
#define LAGOON_MT_WITH_MAKE_FACTORY 1
//
// We don't need to traverse through namespace members.
// Using this CT switch can greatly improve compile times
// and the resulting executable size if namespace member
// traversal is not needed
#define LAGOON_NO_NAMESPACE_MEMBERS 1

#include <mirror/mirror_base.hpp>
#include <mirror/pre_registered/basic.hpp>
#include <mirror/pre_registered/class/std/map.hpp>
#include <mirror/pre_registered/class/std/set.hpp>
#include <lagoon/lagoon.hpp>
#include <lagoon/utils/script_factory.hpp>
#include <iostream>

#include "./tetrahedron.hpp"

int main(void)
{
    try
    {
        using namespace lagoon;
        c_str_script_factory_builder builder;
        c_str_script_factory_input in;
        auto data = in.data();
        //
        typedef std::map<std::string, std::set<std::string> >
            unit_map;
        auto meta_unit_map = reflected_class<unit_map>();
        auto unit_map_factory = meta_unit_map->make_factory(
            builder,
            raw_ptr(&data)
        );
        //
        const char input[] = "{ \
            {'length', {'meter', 'inch', 'foot', 'yard', 'mile', 'furlong'}}, \
            {'area', {'square meter', 'acre'}}, \
            {'volume', {'liter', 'cubic meter', 'gallon', 'pint'}}, \
            {'mass', {'kilogram', 'tonne', 'pound'}}, \
            {'time', {'second', 'minute', 'hour', 'year', 'month', 'day'}}, \
            {'electric current', {'ampere'}}, \
            {'energy', {'joule'}}, \
            {'force', {'newton', 'dyne'}}, \
            {'power', {'watt'}}, \
            {'frequency', {'hertz'}}, \
            {'inductance', {'henry'}}, \
            {'pressure', {'pascal', 'bar', 'atmosphere'}}, \
            {'angle', {'degree', 'radian', 'gradian'}}, \
            {'temperature', {'kelvin', 'degrees celsius', 'degrees fahrenheit'}} \
        }";
        in.set(input, input+sizeof(input));
        raw_ptr punits = unit_map_factory->new_();
        unit_map& units = *raw_cast<unit_map*>(punits);
        for(auto i = units.begin(), e = units.end(); i != e; ++i)
        {
            std::cout << "Some units for '" << i->first << "': '";
            auto j = i->second.begin(), f = i->second.end();
            while(j != f)
            {
                std::cout << *j;
                ++j;
                if(j == f) std::cout << "'.";
                else std::cout << "', '";
            }
            std::cout << std::endl;
        }
        meta_unit_map->delete_(punits);
    }
    catch(std::exception const& error)
    {
        std::cerr << "Error: " << error.what() << std::endl;
    }
    //
    return 0;
}

/* Example of output:
Some units for 'angle': 'degree', 'gradian', 'radian'.
Some units for 'area': 'acre', 'square meter'.
Some units for 'electric current': 'ampere'.
Some units for 'energy': 'joule'.
Some units for 'force': 'dyne', 'newton'.
Some units for 'frequency': 'hertz'.
Some units for 'inductance': 'henry'.
Some units for 'length': 'foot', 'furlong', 'inch', 'meter', 'mile', 'yard'.
Some units for 'mass': 'kilogram', 'pound', 'tonne'.
Some units for 'power': 'watt'.
Some units for 'pressure': 'atmosphere', 'bar', 'pascal'.
Some units for 'temperature': 'degrees celsius', 'degrees fahrenheit', 'kelvin'.
Some units for 'time': 'day', 'hour', 'minute', 'month', 'second', 'year'.
Some units for 'volume': 'cubic meter', 'gallon', 'liter', 'pint'.
 */