Chris@16: /*-----------------------------------------------------------------------------+    
Chris@16: Copyright (c) 2010-2010: Joachim Faulhaber
Chris@16: +------------------------------------------------------------------------------+
Chris@16:    Distributed under the Boost Software License, Version 1.0.
Chris@16:       (See accompanying file LICENCE.txt or copy at
Chris@16:            http://www.boost.org/LICENSE_1_0.txt)
Chris@16: +-----------------------------------------------------------------------------*/
Chris@16: #ifndef BOOST_ICL_TYPE_TRAITS_ON_ABSORBTION_HPP_JOFA_100915
Chris@16: #define BOOST_ICL_TYPE_TRAITS_ON_ABSORBTION_HPP_JOFA_100915
Chris@16: 
Chris@16: namespace boost{ namespace icl
Chris@16: {
Chris@16: 
Chris@16: template<class Type, class Combiner, bool absorbs_identities>
Chris@16: struct on_absorbtion;
Chris@16: 
Chris@16: template<class Type, class Combiner>
Chris@16: struct on_absorbtion<Type, Combiner, false>
Chris@16: {
Chris@16:     typedef on_absorbtion type;
Chris@16:     typedef typename Type::codomain_type codomain_type;
Chris@16: 
Chris@16:     static bool is_absorbable(const codomain_type&){ return false; }
Chris@16: };
Chris@16: 
Chris@16: template<class Type, class Combiner>
Chris@16: struct on_absorbtion<Type, Combiner, true>
Chris@16: {
Chris@16:     typedef on_absorbtion type;
Chris@16:     typedef typename Type::codomain_type codomain_type;
Chris@16:     typedef typename Type::codomain_combine codomain_combine;
Chris@16: 
Chris@16:     static bool is_absorbable(const codomain_type& co_value)
Chris@16:     {
Chris@16:         return co_value == Combiner::identity_element();
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }} // namespace boost icl
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: