trait.hpp

//| This file is a part of the sferes2 framework.
//| Copyright 2009, ISIR / Universite Pierre et Marie Curie (UPMC)
//| Main contributor(s): Jean-Baptiste Mouret, mouret@isir.fr
//|
//| This software is a computer program whose purpose is to facilitate
//| experiments in evolutionary computation and evolutionary robotics.
//|
//| This software is governed by the CeCILL license under French law
//| and abiding by the rules of distribution of free software.  You
//| can use, modify and/ or redistribute the software under the terms
//| of the CeCILL license as circulated by CEA, CNRS and INRIA at the
//| following URL "http://www.cecill.info".
//|
//| As a counterpart to the access to the source code and rights to
//| copy, modify and redistribute granted by the license, users are
//| provided only with a limited warranty and the software's author,
//| the holder of the economic rights, and the successive licensors
//| have only limited liability.
//|
//| In this respect, the user's attention is drawn to the risks
//| associated with loading, using, modifying and/or developing or
//| reproducing the software by the user in light of its specific
//| status of free software, that may mean that it is complicated to
//| manipulate, and that also therefore means that it is reserved for
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//| software's suitability as regards their requirements in conditions
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//| as regards security.
//|
//| The fact that you are presently reading this means that you have
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#ifndef _NN_TRAIT_HPP_
#define _NN_TRAIT_HPP_

// for std::pair
#include <map>
#include <valarray>

#ifdef EIGEN3_ENABLED
#include <Eigen/Core>
#endif

#include "params.hpp"

namespace nn {
  template<typename T>
  struct trait {
    static T zero() {
      return T(0.0f);
    }
    // a 0 initializer for vectors
    static T zero(size_t k) {
      return zero();
    }
    typedef std::valarray<T> vector_t;
    static size_t size(const T& t) {
      return t.size();
    }
    static typename T::type_t single_value(const T& t) {
      assert(t.size() == 1);
      return t.data(0);
    }
  };

  template<>
  struct trait<params::Dummy> {
    typedef std::valarray<float> vector_t;
    static float zero() {
      return 0.0f;
    }
    static float zero(size_t k) {
      return zero();
    }
    static float single_value(const params::Dummy& t) {
      return 0.0f;
    }
    static size_t size(const params::Dummy&) {
      return 0;
    }
  };


  // go with eigen with float (TODO : double)
  template<>
  struct trait<float> {
    typedef Eigen::VectorXf vector_t;
    static float zero() {
      return 0.0f;
    }
    static vector_t zero(size_t k) {
      return Eigen::VectorXf::Zero(k);
    }
    static float single_value(const float& t) {
      return t;
    }
    static size_t size(const float& t) {
      return 1;
    }
  };

  template<>
  struct trait<std::pair<float, float> > {
    typedef std::valarray<std::pair<float, float> > vector_t;
    static std::pair<float, float> zero() {
      return std::make_pair(0.0f, 0.0f);
    }
    static std::pair<float, float> zero(size_t k) {
      return zero();
    }
    static float single_value(const std::pair<float, float>& t) {
      return t.first;
    }
    static size_t size(const std::pair<float, float>& t) {
      return 2;
    }
  };

  // useful but wrong place (?)
  template<typename _CharT, typename _Traits>
  static std::basic_ostream<_CharT, _Traits>&
  operator<<(std::basic_ostream<_CharT, _Traits>& ofs, const std::pair<float, float>& p) {
    return ofs<<p.first<<" "<<p.second;
  }

  template<typename _CharT, typename _Traits>
  static std::basic_ostream<_CharT, _Traits>&
  operator<<(std::basic_ostream<_CharT, _Traits>& ofs, const std::vector<float>& p) {
    for (size_t i = 0; i < p.size(); ++i)
      ofs<<p[i]<<" ";
    return ofs;
  }


  template<typename T1, typename T2>
  static std::istream& operator>>(std::istream& ifs, std::pair<T1, T2>& p) {
    T1 t1;
    T2 t2;
    ifs >> t1;
    ifs >> t2;
    return std::make_pair(t1, t2);
  }

}


#endif