boost/random/detail/pass_through_engine.hpp

   1 /* boost random/detail/uniform_int_float.hpp header file
   2  *
   3  * Copyright Jens Maurer 2000-2001
   4  * Distributed under the Boost Software License, Version 1.0. (See
   5  * accompanying file LICENSE_1_0.txt or copy at
   6  * http://www.boost.org/LICENSE_1_0.txt)
   7  *
   8  * See http://www.boost.org for most recent version including documentation.
   9  *
  10  * $Id: pass_through_engine.hpp 58649 2010-01-02 21:23:17Z steven_watanabe $
  11  *
  12  */
  13
  14 #ifndef BOOST_RANDOM_DETAIL_PASS_THROUGH_ENGINE_HPP
  15 #define BOOST_RANDOM_DETAIL_PASS_THROUGH_ENGINE_HPP
  16
  17 #include <boost/config.hpp>
  18 #include <boost/random/detail/ptr_helper.hpp>
  19 #include <boost/random/detail/disable_warnings.hpp>
  20
  21 namespace boost {
  22 namespace random {
  23 namespace detail {
  24
  25 template<class UniformRandomNumberGenerator>
  26 class pass_through_engine
  27 {
  28 private:
  29   typedef ptr_helper<UniformRandomNumberGenerator> helper_type;
  30
  31 public:
  32   typedef typename helper_type::value_type base_type;
  33   typedef typename base_type::result_type result_type;
  34
  35   explicit pass_through_engine(UniformRandomNumberGenerator rng)
  36     // make argument an rvalue to avoid matching Generator& constructor
  37     : _rng(static_cast<typename helper_type::rvalue_type>(rng))
  38   { }
  39
  40   result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (base().min)(); }
  41   result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (base().max)(); }
  42   base_type& base() { return helper_type::ref(_rng); }
  43   const base_type& base() const { return helper_type::ref(_rng); }
  44
  45   result_type operator()() { return base()(); }
  46
  47 private:
  48   UniformRandomNumberGenerator _rng;
  49 };
  50
  51 #ifndef BOOST_NO_STD_LOCALE
  52
  53 template<class UniformRandomNumberGenerator, class CharT, class Traits>
  54 std::basic_ostream<CharT,Traits>&
  55 operator<<(
  56     std::basic_ostream<CharT,Traits>& os
  57     , const pass_through_engine<UniformRandomNumberGenerator>& ud
  58     )
  59 {
  60     return os << ud.base();
  61 }
  62
  63 template<class UniformRandomNumberGenerator, class CharT, class Traits>
  64 std::basic_istream<CharT,Traits>&
  65 operator>>(
  66     std::basic_istream<CharT,Traits>& is
  67     , const pass_through_engine<UniformRandomNumberGenerator>& ud
  68     )
  69 {
  70     return is >> ud.base();
  71 }
  72
  73 #else // no new streams
  74
  75 template<class UniformRandomNumberGenerator>
  76 inline std::ostream&
  77 operator<<(std::ostream& os,
  78            const pass_through_engine<UniformRandomNumberGenerator>& ud)
  79 {
  80     return os << ud.base();
  81 }
  82
  83 template<class UniformRandomNumberGenerator>
  84 inline std::istream&
  85 operator>>(std::istream& is,
  86            const pass_through_engine<UniformRandomNumberGenerator>& ud)
  87 {
  88     return is >> ud.base();
  89 }
  90
  91 #endif
  92
  93 } // namespace detail
  94 } // namespace random
  95 } // namespace boost
  96
  97 #include <boost/random/detail/enable_warnings.hpp>
  98
  99 #endif // BOOST_RANDOM_DETAIL_PASS_THROUGH_ENGINE_HPP
 100