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         *
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#ifndef CORELIB_DATASOURCE_HPP
#define CORELIB_DATASOURCE_HPP

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

#include "DataSourceBase.hpp"

namespace RTT
{

#ifndef ORO_EMBEDDED

    struct RTT_EXPORT bad_assignment
    {
    };
#endif


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

  public:
      typedef typename boost::remove_const<typename boost::remove_reference<T>::type>::type value_t;
      typedef T result_t;

      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 bool evaluate() const;

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

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

      virtual std::string getType() const;

      static  std::string GetType();

      virtual const TypeInfo* getTypeInfo() const;

      static const TypeInfo* GetTypeInfo();

      static  std::string GetTypeName();

      virtual std::string getTypeName() const;

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

  };

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

      // For assignment from another datasource, we use the call_traits convention but
      // remove the 'const' for the 'small' types. This to avoid requiring a DataSourceAdaptor.
      // Big types (classes) are still passed by const&.
      typedef typename boost::remove_const<typename boost::call_traits<value_t>::param_type>::type copy_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;

      virtual const_reference_t rvalue() const = 0;

      virtual bool update( DataSourceBase* other );

      virtual CommandInterface* updateCommand( DataSourceBase* other);

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

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

      virtual bool updateBlob(int protocol, const void* data);

      virtual void* server(int protocol, void* data );

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

  };
}

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