DataSource.hpp

/***************************************************************************
  tag: Peter Soetens  Mon Jan 19 14:11:25 CET 2004  DataSource.hpp

                        DataSource.hpp -  description
                           -------------------
    begin                : Mon January 19 2004
    copyright            : (C) 2004 Peter Soetens
    email                : peter.soetens@mech.kuleuven.ac.be

 ***************************************************************************
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU General Public                   *
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 *   version 2 of the License.                                             *
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 *   software library without restriction.  Specifically, if other files   *
 *   instantiate templates or use macros or inline functions from this     *
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 *   resulting executable to be covered by the GNU General Public          *
 *   License.  This exception does not however invalidate any other        *
 *   reasons why the executable file might be covered by the GNU General   *
 *   Public License.                                                       *
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 ***************************************************************************/

#ifndef CORELIB_DATASOURCE_HPP
#define CORELIB_DATASOURCE_HPP

#include <map>
#include <string>
#include <exception>
#include "../rtt-config.h"
#include <boost/call_traits.hpp>
#include <boost/static_assert.hpp>
#include <boost/type_traits/add_reference.hpp>
#include <boost/type_traits/add_const.hpp>

#include "../base/DataSourceBase.hpp"

namespace RTT
{ namespace internal {


#ifndef ORO_EMBEDDED

    struct RTT_API bad_assignment : public std::exception
    {
        virtual ~bad_assignment() throw();
        virtual const char* what() const throw();
    };
#endif

  namespace details
  {
     template<typename X>
     struct HasConst
     { static const int value = 0; };
     template<typename X>
     struct HasConst<X const>
     { static const int value = 1; };

     template<typename X>
     struct GetConstRef
     { typedef typename boost::add_reference<typename boost::add_const<X>::type>::type type; };
     template<>
     struct GetConstRef<void>
     { typedef void type; };
  }

  template<typename T>
  class DataSource
    : public base::DataSourceBase
  {
  protected:
      virtual ~DataSource();

  public:

      typedef T value_t;
      typedef T result_t;
      typedef typename details::GetConstRef<T>::type const_reference_t;

      BOOST_STATIC_ASSERT( !details::HasConst<T>::value );

      typedef typename boost::intrusive_ptr<DataSource<T> > shared_ptr;

      typedef typename boost::intrusive_ptr<const DataSource<T> > const_ptr;

      virtual result_t get() const = 0;

      virtual result_t value() const = 0;

      virtual const_reference_t rvalue() const = 0;

      void const* getRawConstPointer() { return &rvalue(); }

      virtual bool evaluate() const;

      virtual DataSource<T>* clone() const = 0;

      virtual DataSource<T>* copy( std::map<const base::DataSourceBase*, base::DataSourceBase*>& alreadyCloned ) const = 0;

      virtual std::string getType() const;

      static  std::string GetType();

      virtual const types::TypeInfo* getTypeInfo() const;

      static const types::TypeInfo* GetTypeInfo();

      static  std::string GetTypeName();

      virtual std::string getTypeName() const;

      static DataSource<T>* narrow(base::DataSourceBase* db);

  };

  template<typename T>
  class AssignableDataSource
    : public DataSource<T>
  {
  protected:
      ~AssignableDataSource();
  public:
      typedef typename DataSource<T>::value_t value_t;
      typedef typename DataSource<T>::const_reference_t const_reference_t;
      typedef typename boost::call_traits<value_t>::param_type param_t;
      typedef typename boost::call_traits<value_t>::reference reference_t;

      typedef boost::intrusive_ptr<AssignableDataSource<T> > shared_ptr;
      typedef typename boost::intrusive_ptr<const AssignableDataSource<T> > const_ptr;

      virtual void set( param_t t ) = 0;

      virtual reference_t set() = 0;

      void* getRawPointer() { return &set(); }

      virtual bool isAssignable() const { return true; }

      virtual bool update( base::DataSourceBase* other );

      virtual base::ActionInterface* updateAction( base::DataSourceBase* other);

      virtual AssignableDataSource<T>* clone() const = 0;

      virtual AssignableDataSource<T>* copy( std::map<const base::DataSourceBase*, base::DataSourceBase*>& alreadyCloned ) const = 0;

      static AssignableDataSource<T>* narrow(base::DataSourceBase* db);

  };
}}

// workaround inclusion dependencies.
#ifndef ORO_CORELIB_DATASOURCES_HPP
#include "DataSource.inl"
#endif
#endif