root/tlate/overriding_structured_value.hh

/*  This file is part of Alue, the multiprotocol Internet discussion daemon

    Copyright © 2009 Antti-Juhani Kaijanaho

    Alue is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Alue is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Alue.  If not, see <http://www.gnu.org/licenses/>.

 */

#ifndef GUARD_TLATE_OVERRIDING_STRUCTURED_VALUE_HH
#define GUARD_TLATE_OVERRIDING_STRUCTURED_VALUE_HH

#include "lazy_structured_value.hh"

namespace tlate
{
        class overriding_structured_value : public lazy_structured_value
        {
        public:
                typedef boost::shared_ptr<overriding_structured_value> ptr;
                typedef boost::shared_ptr<const overriding_structured_value>
                const_ptr;

                explicit overriding_structured_value(structured_value::const_ptr computer)
                        : lazy_structured_value(computer)
                        {}
                
                void override(std::string key, value::const_ptr val) {
                        boost::lock_guard<boost::mutex> lg(mt);
                        if (val)
                                memo[key] = val;
                        else
                                memo[key].reset(new missing_value);
                }
        };
}

#endif /* GUARD_TLATE_OVERRIDING_STRUCTURED_VALUE_HH */