williamr@2: /* boost random/uniform_01.hpp header file
williamr@2:  *
williamr@2:  * Copyright Jens Maurer 2000-2001
williamr@2:  * Distributed under the Boost Software License, Version 1.0. (See
williamr@2:  * accompanying file LICENSE_1_0.txt or copy at
williamr@2:  * http://www.boost.org/LICENSE_1_0.txt)
williamr@2:  *
williamr@2:  * See http://www.boost.org for most recent version including documentation.
williamr@2:  *
williamr@2:  * $Id: uniform_01.hpp,v 1.18 2004/07/27 03:43:32 dgregor Exp $
williamr@2:  *
williamr@2:  * Revision history
williamr@2:  *  2001-02-18  moved to individual header files
williamr@2:  */
williamr@2: 
williamr@2: #ifndef BOOST_RANDOM_UNIFORM_01_HPP
williamr@2: #define BOOST_RANDOM_UNIFORM_01_HPP
williamr@2: 
williamr@2: #include <iostream>
williamr@2: #include <boost/config.hpp>
williamr@2: #include <boost/limits.hpp>
williamr@2: #include <boost/static_assert.hpp>
williamr@2: 
williamr@2: namespace boost {
williamr@2: 
williamr@2: // Because it is so commonly used: uniform distribution on the real [0..1)
williamr@2: // range.  This allows for specializations to avoid a costly int -> float
williamr@2: // conversion plus float multiplication
williamr@2: template<class UniformRandomNumberGenerator, class RealType = double>
williamr@2: class uniform_01
williamr@2: {
williamr@2: public:
williamr@2:   typedef UniformRandomNumberGenerator base_type;
williamr@2:   typedef RealType result_type;
williamr@2: 
williamr@2:   BOOST_STATIC_CONSTANT(bool, has_fixed_range = false);
williamr@2: 
williamr@2: #if !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) && !(defined(BOOST_MSVC) && BOOST_MSVC <= 1300)
williamr@2:   BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer);
williamr@2: #endif
williamr@2: 
williamr@2:   explicit uniform_01(base_type rng)
williamr@2:     : _rng(rng),
williamr@2:       _factor(result_type(1) /
williamr@2:               (result_type((_rng.max)()-(_rng.min)()) +
williamr@2:                result_type(std::numeric_limits<base_result>::is_integer ? 1 : 0)))
williamr@2:   {
williamr@2:   }
williamr@2:   // compiler-generated copy ctor and copy assignment are fine
williamr@2: 
williamr@2:   result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return result_type(0); }
williamr@2:   result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return result_type(1); }
williamr@2:   base_type& base() { return _rng; }
williamr@2:   const base_type& base() const { return _rng; }
williamr@2:   void reset() { }
williamr@2: 
williamr@2:   result_type operator()() {
williamr@2:     return result_type(_rng() - (_rng.min)()) * _factor;
williamr@2:   }
williamr@2: 
williamr@2: #if !defined(BOOST_NO_OPERATORS_IN_NAMESPACE) && !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
williamr@2:   template<class CharT, class Traits>
williamr@2:   friend std::basic_ostream<CharT,Traits>&
williamr@2:   operator<<(std::basic_ostream<CharT,Traits>& os, const uniform_01& u)
williamr@2:   {
williamr@2:     os << u._rng;
williamr@2:     return os;
williamr@2:   }
williamr@2: 
williamr@2:   template<class CharT, class Traits>
williamr@2:   friend std::basic_istream<CharT,Traits>&
williamr@2:   operator>>(std::basic_istream<CharT,Traits>& is, uniform_01& u)
williamr@2:   {
williamr@2:     is >> u._rng;
williamr@2:     return is;
williamr@2:   }
williamr@2: #endif
williamr@2: 
williamr@2: private:
williamr@2:   typedef typename base_type::result_type base_result;
williamr@2:   base_type _rng;
williamr@2:   result_type _factor;
williamr@2: };
williamr@2: 
williamr@2: #ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
williamr@2: //  A definition is required even for integral static constants
williamr@2: template<class UniformRandomNumberGenerator, class RealType>
williamr@2: const bool uniform_01<UniformRandomNumberGenerator, RealType>::has_fixed_range;
williamr@2: #endif
williamr@2: 
williamr@2: } // namespace boost
williamr@2: 
williamr@2: #endif // BOOST_RANDOM_UNIFORM_01_HPP