/*
  Implementation of Lambert W function

  Copyright (C) 2009 Darko Veberic, darko.veberic@ung.si

  This program 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.

  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef _LambertW_h_
#define _LambertW_h_

#include <limits>


template<int branch>
double LambertWApproximation(const double x);

template<int branch>
double LambertW(const double x);

inline
double
LambertW(const int branch, const double x)
{
  switch (branch) {
  case -1: return LambertW<-1>(x);
  case  0: return LambertW<0>(x);
  default: return std::numeric_limits<double>::quiet_NaN();
  }
}


#endif