maintain/src/geometry2/tf2/include/tf2/convert.h

/*
 * Copyright (c) 2013, Open Source Robotics Foundation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
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 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Willow Garage, Inc. nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 */

/** \author Tully Foote */

#ifndef TF2_CONVERT_H
#define TF2_CONVERT_H


#include <tf2/transform_datatypes.h>
#include <tf2/exceptions.h>
#include <geometry_msgs/TransformStamped.h>
#include <tf2/impl/convert.h>

namespace tf2 {

/**\brief The templated function expected to be able to do a transform
 *
 * This is the method which tf2 will use to try to apply a transform for any given datatype.   
 * \param data_in The data to be transformed.
 * \param data_out A reference to the output data.  Note this can point to data in and the method should be mutation safe.
 * \param transform The transform to apply to data_in to fill data_out.  
 * 
 * This method needs to be implemented by client library developers
 */
template <class T>
  void doTransform(const T& data_in, T& data_out, const geometry_msgs::TransformStamped& transform);

/**\brief Get the timestamp from data 
 * \param t The data input.
 * \return The timestamp associated with the data. The lifetime of the returned
 * reference is bound to the lifetime of the argument.
 */
template <class T>
  const ros::Time& getTimestamp(const T& t);

/**\brief Get the frame_id from data 
 * \param t The data input.
 * \return The frame_id associated with the data. The lifetime of the returned
 * reference is bound to the lifetime of the argument.
 */
template <class T>
  const std::string& getFrameId(const T& t);



/* An implementation for Stamped<P> datatypes */
template <class P>
  const ros::Time& getTimestamp(const tf2::Stamped<P>& t)
  {
    return t.stamp_;
  }

/* An implementation for Stamped<P> datatypes */
template <class P>
  const std::string& getFrameId(const tf2::Stamped<P>& t)
  {
    return t.frame_id_;
  }

/** Function that converts from one type to a ROS message type. It has to be
 * implemented by each data type in tf2_* (except ROS messages) as it is
 * used in the "convert" function.
 * \param a an object of whatever type
 * \return the conversion as a ROS message
 */
template<typename A, typename B>
  B toMsg(const A& a);

/** Function that converts from a ROS message type to another type. It has to be
 * implemented by each data type in tf2_* (except ROS messages) as it is used
 * in the "convert" function.
 * \param a a ROS message to convert from
 * \param b the object to convert to
 */
template<typename A, typename B>
  void fromMsg(const A&, B& b);

/** Function that converts any type to any type (messages or not).
 * Matching toMsg and from Msg conversion functions need to exist.
 * If they don't exist or do not apply (for example, if your two
 * classes are ROS messages), just write a specialization of the function.
 * \param a an object to convert from
 * \param b the object to convert to
 */
template <class A, class B>
  void convert(const A& a, B& b)
  {
    //printf("In double type convert\n");
    impl::Converter<ros::message_traits::IsMessage<A>::value, ros::message_traits::IsMessage<B>::value>::convert(a, b);
  }

template <class A>
  void convert(const A& a1, A& a2)
  {
    //printf("In single type convert\n");
    if(&a1 != &a2)
      a2 = a1;
  }


}

#endif //TF2_CONVERT_H