BuilderFrom.h

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/***************************************************************************
 *
 * Copyright (C) 2009-2011 Cassio Neri Moreira
 *
 * This file is part of the KeyValue library.
 *
 * The KeyValue library 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.
 *
 * The KeyValue library 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 KeyValue. If not, see <http://www.gnu.org/licenses/>.
 *
 * If you modify this library, or any covered work, by linking or combining
 * it with Excel (or a modified version of that program), containing parts
 * covered by the terms of End-User License Agreement for Microsoft
 * Software, the licensors of KeyValue grant you additional permission to
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 **************************************************************************/

#ifndef KEYVALUE_MNGT_BUILDERFROM_H_
#define KEYVALUE_MNGT_BUILDERFROM_H_

#include <boost/static_assert.hpp>

#include "keyvalue/frontend/LexicalToolKit.h"
#include "keyvalue/mngt/AbstractBuilder.h"
#include "keyvalue/sys/exception/Exception.h"
#include "keyvalue/util/IsBasic.h"
#include "keyvalue/value/PtrTraits.h"
#include "keyvalue/value/Variant.h"

namespace keyvalue {

#ifdef DOXYGEN
  template <typename ObjectType, typename InputType>
  class BuilderFrom {};
#endif

template <typename ObjectType, typename InputType>
class BuilderFrom;

template <typename ObjectType>
class BuilderFrom<ObjectType, value::Variant> :

  public AbstractBuilder {

public:

  virtual typename value::PtrTraits<ObjectType>::Type_
  getObject(const value::Variant& data) const = 0;

}; // class BuilderFrom<ObjectType, value::Variant>

template <typename ObjectType, typename InputType>
class BuilderFrom :

  public BuilderFrom<ObjectType, value::Variant> {

public:

  typename value::PtrTraits<ObjectType>::Type_
  getObject(const value::Variant& data) const;

private:

  virtual typename value::PtrTraits<ObjectType>::Type_
  getObject(const InputType& data) const = 0;

  /*
   ATTENTION: If you get a compiler error here about

   '::boost::STATIC_ASSERTION_FAILURE<x>'

   this means that you have defined BUILDS_FROM to something different from
   bool, double, string, ptime and unsigned int.
   */
  BOOST_STATIC_ASSERT(util::IsBasic<InputType>::value);

}; // class BuilderFrom

/*--------------------------------------------------------------------------
 * getObject()
 *------------------------------------------------------------------------*/

template <typename ObjectType, typename InputType>
typename value::PtrTraits<ObjectType>::Type_
BuilderFrom<ObjectType, InputType>::getObject(const value::Variant& data)
  const {

  using frontend::LexicalToolKit;

  if (data.is<InputType>(LexicalToolKit::input))
    return getObject(data.get<InputType>(LexicalToolKit::input));

  throw RuntimeError() & "Builder '" & Processor::getName() & "' cannot "
    "build from input '" & data & "'!";
}

} // namespace keyvalue

#endif // KEYVALUE_MNGT_BUILDERFROM_H_