/* boost random/uniform_real.hpp header file

 *

 * Copyright Jens Maurer 2000-2001

 * Distributed under the Boost Software License, Version 1.0. (See

 * accompanying file LICENSE_1_0.txt or copy at

 * http://www.boost.org/LICENSE_1_0.txt)

 *

 * See http://www.boost.org for most recent version including documentation.

 *

 * $Id: uniform_real.hpp,v 1.17 2005/01/28 15:04:17 dgregor Exp $

 *

 * Revision history

 *  2001-04-08  added min<max assertion (N. Becker)

 *  2001-02-18  moved to individual header files

 */

#ifndef BOOST_RANDOM_UNIFORM_REAL_HPP

#define BOOST_RANDOM_UNIFORM_REAL_HPP

#include <cassert>

#include <iostream>

#include <boost/config.hpp>

#include <boost/limits.hpp>

#include <boost/static_assert.hpp>

namespace boost {

// uniform distribution on a real range

template<class RealType = double>

class uniform_real

{

public:

  typedef RealType input_type;

  typedef RealType result_type;

  explicit uniform_real(RealType min = RealType(0),

                        RealType max = RealType(1))

    : _min(min), _max(max)

  {

#ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS

    BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer);

#endif

    assert(min < max);

  }

  // compiler-generated copy ctor and assignment operator are fine

  result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return _min; }

  result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return _max; }

  void reset() { }

  template<class Engine>

  result_type operator()(Engine& eng) {

    return static_cast<result_type>(eng() - eng.min BOOST_PREVENT_MACRO_SUBSTITUTION())

           / static_cast<result_type>(eng.max BOOST_PREVENT_MACRO_SUBSTITUTION() - eng.min BOOST_PREVENT_MACRO_SUBSTITUTION())

           * (_max - _min) + _min;

  }

#if !defined(BOOST_NO_OPERATORS_IN_NAMESPACE) && !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)

  template<class CharT, class Traits>

  friend std::basic_ostream<CharT,Traits>&

  operator<<(std::basic_ostream<CharT,Traits>& os, const uniform_real& ud)

  {

    os << ud._min << " " << ud._max;

    return os;

  }

  template<class CharT, class Traits>

  friend std::basic_istream<CharT,Traits>&

  operator>>(std::basic_istream<CharT,Traits>& is, uniform_real& ud)

  {

    is >> std::ws >> ud._min >> std::ws >> ud._max;

    return is;

  }

#endif

private:

  RealType _min, _max;

};

} // namespace boost

#endif // BOOST_RANDOM_UNIFORM_REAL_HPP