epoc32/include/stdapis/boost/random/discard_block.hpp
author William Roberts <williamr@symbian.org>
Wed, 31 Mar 2010 12:33:34 +0100
branchSymbian3
changeset 4 837f303aceeb
permissions -rw-r--r--
Current Symbian^3 public API header files (from PDK 3.0.h)
This is the epoc32/include tree with the "platform" subtrees removed, and
all but a selected few mbg and rsg files removed.
     1 /* boost random/discard_block.hpp header file
     2  *
     3  * Copyright Jens Maurer 2002
     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: discard_block.hpp,v 1.12 2005/05/21 15:57:00 dgregor Exp $
    11  *
    12  * Revision history
    13  *  2001-03-02  created
    14  */
    15 
    16 #ifndef BOOST_RANDOM_DISCARD_BLOCK_HPP
    17 #define BOOST_RANDOM_DISCARD_BLOCK_HPP
    18 
    19 #include <iostream>
    20 #include <boost/config.hpp>
    21 #include <boost/limits.hpp>
    22 #include <boost/static_assert.hpp>
    23 
    24 
    25 namespace boost {
    26 namespace random {
    27 
    28 template<class UniformRandomNumberGenerator, unsigned int p, unsigned int r>
    29 class discard_block
    30 {
    31 public:
    32   typedef UniformRandomNumberGenerator base_type;
    33   typedef typename base_type::result_type result_type;
    34 
    35   BOOST_STATIC_CONSTANT(bool, has_fixed_range = false);
    36   BOOST_STATIC_CONSTANT(unsigned int, total_block = p);
    37   BOOST_STATIC_CONSTANT(unsigned int, returned_block = r);
    38 
    39 #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
    40   BOOST_STATIC_ASSERT(total_block >= returned_block);
    41 #endif
    42 
    43   discard_block() : _rng(), _n(0) { }
    44   explicit discard_block(const base_type & rng) : _rng(rng), _n(0) { }
    45   template<class It> discard_block(It& first, It last)
    46     : _rng(first, last), _n(0) { }
    47   void seed() { _rng.seed(); _n = 0; }
    48   template<class T> void seed(T s) { _rng.seed(s); _n = 0; }
    49   template<class It> void seed(It& first, It last)
    50   { _n = 0; _rng.seed(first, last); }
    51 
    52   const base_type& base() const { return _rng; }
    53 
    54   result_type operator()()
    55   {
    56     if(_n >= returned_block) {
    57       // discard values of random number generator
    58       for( ; _n < total_block; ++_n)
    59         _rng();
    60       _n = 0;
    61     }
    62     ++_n;
    63     return _rng();
    64   }
    65 
    66   result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (_rng.min)(); }
    67   result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (_rng.max)(); }
    68   static bool validation(result_type x) { return true; }  // dummy
    69 
    70 #ifndef BOOST_NO_OPERATORS_IN_NAMESPACE
    71 
    72 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
    73   template<class CharT, class Traits>
    74   friend std::basic_ostream<CharT,Traits>&
    75   operator<<(std::basic_ostream<CharT,Traits>& os, const discard_block& s)
    76   {
    77     os << s._rng << " " << s._n << " ";
    78     return os;
    79   }
    80 
    81   template<class CharT, class Traits>
    82   friend std::basic_istream<CharT,Traits>&
    83   operator>>(std::basic_istream<CharT,Traits>& is, discard_block& s)
    84   {
    85     is >> s._rng >> std::ws >> s._n >> std::ws;
    86     return is;
    87   }
    88 #endif
    89 
    90   friend bool operator==(const discard_block& x, const discard_block& y)
    91   { return x._rng == y._rng && x._n == y._n; }
    92   friend bool operator!=(const discard_block& x, const discard_block& y)
    93   { return !(x == y); }
    94 #else
    95   // Use a member function; Streamable concept not supported.
    96   bool operator==(const discard_block& rhs) const
    97   { return _rng == rhs._rng && _n == rhs._n; }
    98   bool operator!=(const discard_block& rhs) const
    99   { return !(*this == rhs); }
   100 #endif
   101 
   102 private:
   103   base_type _rng;
   104   unsigned int _n;
   105 };
   106 
   107 #ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
   108 //  A definition is required even for integral static constants
   109 template<class UniformRandomNumberGenerator, unsigned int p, unsigned int r>
   110 const bool discard_block<UniformRandomNumberGenerator, p, r>::has_fixed_range;
   111 template<class UniformRandomNumberGenerator, unsigned int p, unsigned int r>
   112 const unsigned int discard_block<UniformRandomNumberGenerator, p, r>::total_block;
   113 template<class UniformRandomNumberGenerator, unsigned int p, unsigned int r>
   114 const unsigned int discard_block<UniformRandomNumberGenerator, p, r>::returned_block;
   115 #endif
   116 
   117 } // namespace random
   118 
   119 } // namespace boost
   120 
   121 #endif // BOOST_RANDOM_DISCARD_BLOCK_HPP