ensure.hh

00001 // This file is a part of Aurelia.
00002 // Copyright (C) 2010  Valentin David
00003 // Copyright (C) 2010  University of Bergen
00004 //
00005 // This program is free software: you can redistribute it and/or modify
00006 // it under the terms of the GNU General Public License as published by
00007 // the Free Software Foundation, either version 3 of the License, or
00008 // (at your option) any later version.
00009 //
00010 // This program is distributed in the hope that it will be useful,
00011 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00012 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013 // GNU General Public License for more details.
00014 //
00015 // You should have received a copy of the GNU General Public License
00016 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
00017 #ifndef __ENSURE_HH
00018 # define __ENSURE_HH
00019 
00020 # include "../failure.hh"
00021 
00022 namespace aurelia {
00023 
00024   template <typename Strat, typename T>
00025   struct only_for_strategy {
00026     Strat s;
00027     only_for_strategy(const Strat& s): s(s) {}
00028   template <typename T>
00029   struct ensure {
00030     T operator()(T&& in) const {
00031       return std::move(in);
00032     }
00033 
00034     T operator()(const T& in) const {
00035       return in;
00036     }
00037 
00038     template <typename U>
00039     T operator()(U) const {
00040       throw failure();
00041     }
00042   };
00043 
00044 }
00045 
00046 #endif