factory.hh

Go to the documentation of this file.

/* -*- C++ -*-
 * $Id: factory.hh 957 2005-03-07 16:01:20Z sjoyeux $
 */
#ifndef UTILMM_TYPES_FACTORY_HEADER
# define UTILMM_TYPES_FACTORY_HEADER
#include "utilmm/config/config.h"

#include "boost/utility.hpp"

#include "utilmm/singleton/wrapper_fwd.hh"
#include "utilmm/functional/arg_traits.hh"

#include "utilmm/types/factory_fwd.hh"
#include "utilmm/types/bits/factory_error.hh"

namespace utilmm {

  template< class AbstractProduct, typename IdentifierType, typename Result,
            typename ProductCreator,
            template<typename, class, typename> class FactoryErrorPolicy,
            class OrderId >
  class factory
    :public FactoryErrorPolicy<IdentifierType, AbstractProduct, Result>,
     public boost::noncopyable {
  private:
    typedef typename arg_traits<IdentifierType>::type id_param;
    typedef typename arg_traits<ProductCreator>::type creator_param;

    typedef std::map<IdentifierType, ProductCreator, OrderId> factory_db;
    
    factory_db associations;

  public:
    bool add(id_param id, creator_param creator) {
      typename factory_db::value_type to_add(id, creator);

      return associations.insert(to_add).second;
    }
    bool remove(id_param id) {
      return associations.erase(id)==1;
    }

    bool make_alias(id_param from, id_param to) {
      typename factory_db::iterator i = associations.find(to);
      
      return associations.end()==i || add(from, i->second);
    }

    Result create(id_param id) {
      typename factory_db::iterator i = associations.find(id);
      
      if( associations.end()==i )
        return this->on_unknown_id(id);
      else
        return (i->second)();
    }

    bool check_entry(id_param id) const {
      return associations.find(id)!=associations.end();
    }

    ProductCreator const &get_creator(id_param id) const {
      typename factory_db::const_iterator i = associations.find(id);
      
      if( associations.end()==i )
        return this->on_unknown_type(id);
      else
        return i->second;
    }
    
  private:
    factory() {}
    ~factory() {}

    template<class Ty>
    friend class singleton::wrapper;
  }; // class utilmm::factory<>
            
} // namespace utilmm

# define IN_UTILMM_TYPES_FACTORY_HEADER
#include "utilmm/types/bits/factory.tcc"
# undef IN_UTILMM_TYPES_FACTORY_HEADER
#endif // UTILMM_TYPES_FACTORY_HEADER