// abstract factory: locate items by string id
    memo::factory< std::string > factory;
    // inscribe items of any kind (textures, anims, maps, texts...)
    factory["numbers"] = std::vector<int>( {1,2,3,4,5} );
    factory["names"] = std::list<std::string>( {"john", "mark", "tony"} );
    // clone items (implicit casting)
    std::vector<int> numbers = factory["numbers"];
    // clone items (explicit casting)
    std::list<std::string> names = factory["names"].as< std::list<std::string> >();
    // tests
    assert( 5 == numbers.size() );
    assert( 3 == names.size() );
    // delete items on factory destruction