williamr@2: /* boost random/discard_block.hpp header file williamr@2: * williamr@2: * Copyright Jens Maurer 2002 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: discard_block.hpp,v 1.12 2005/05/21 15:57:00 dgregor Exp $ williamr@2: * williamr@2: * Revision history williamr@2: * 2001-03-02 created williamr@2: */ williamr@2: williamr@2: #ifndef BOOST_RANDOM_DISCARD_BLOCK_HPP williamr@2: #define BOOST_RANDOM_DISCARD_BLOCK_HPP williamr@2: williamr@2: #include williamr@2: #include williamr@2: #include williamr@2: #include williamr@2: williamr@2: williamr@2: namespace boost { williamr@2: namespace random { williamr@2: williamr@2: template williamr@2: class discard_block williamr@2: { williamr@2: public: williamr@2: typedef UniformRandomNumberGenerator base_type; williamr@2: typedef typename base_type::result_type result_type; williamr@2: williamr@2: BOOST_STATIC_CONSTANT(bool, has_fixed_range = false); williamr@2: BOOST_STATIC_CONSTANT(unsigned int, total_block = p); williamr@2: BOOST_STATIC_CONSTANT(unsigned int, returned_block = r); williamr@2: williamr@2: #ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS williamr@2: BOOST_STATIC_ASSERT(total_block >= returned_block); williamr@2: #endif williamr@2: williamr@2: discard_block() : _rng(), _n(0) { } williamr@2: explicit discard_block(const base_type & rng) : _rng(rng), _n(0) { } williamr@2: template discard_block(It& first, It last) williamr@2: : _rng(first, last), _n(0) { } williamr@2: void seed() { _rng.seed(); _n = 0; } williamr@2: template void seed(T s) { _rng.seed(s); _n = 0; } williamr@2: template void seed(It& first, It last) williamr@2: { _n = 0; _rng.seed(first, last); } williamr@2: williamr@2: const base_type& base() const { return _rng; } williamr@2: williamr@2: result_type operator()() williamr@2: { williamr@2: if(_n >= returned_block) { williamr@2: // discard values of random number generator williamr@2: for( ; _n < total_block; ++_n) williamr@2: _rng(); williamr@2: _n = 0; williamr@2: } williamr@2: ++_n; williamr@2: return _rng(); williamr@2: } williamr@2: williamr@2: result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (_rng.min)(); } williamr@2: result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (_rng.max)(); } williamr@2: static bool validation(result_type x) { return true; } // dummy williamr@2: williamr@2: #ifndef BOOST_NO_OPERATORS_IN_NAMESPACE williamr@2: williamr@2: #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS williamr@2: template williamr@2: friend std::basic_ostream& williamr@2: operator<<(std::basic_ostream& os, const discard_block& s) williamr@2: { williamr@2: os << s._rng << " " << s._n << " "; williamr@2: return os; williamr@2: } williamr@2: williamr@2: template williamr@2: friend std::basic_istream& williamr@2: operator>>(std::basic_istream& is, discard_block& s) williamr@2: { williamr@2: is >> s._rng >> std::ws >> s._n >> std::ws; williamr@2: return is; williamr@2: } williamr@2: #endif williamr@2: williamr@2: friend bool operator==(const discard_block& x, const discard_block& y) williamr@2: { return x._rng == y._rng && x._n == y._n; } williamr@2: friend bool operator!=(const discard_block& x, const discard_block& y) williamr@2: { return !(x == y); } williamr@2: #else williamr@2: // Use a member function; Streamable concept not supported. williamr@2: bool operator==(const discard_block& rhs) const williamr@2: { return _rng == rhs._rng && _n == rhs._n; } williamr@2: bool operator!=(const discard_block& rhs) const williamr@2: { return !(*this == rhs); } williamr@2: #endif williamr@2: williamr@2: private: williamr@2: base_type _rng; williamr@2: unsigned int _n; 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 williamr@2: const bool discard_block::has_fixed_range; williamr@2: template williamr@2: const unsigned int discard_block::total_block; williamr@2: template williamr@2: const unsigned int discard_block::returned_block; williamr@2: #endif williamr@2: williamr@2: } // namespace random williamr@2: williamr@2: } // namespace boost williamr@2: williamr@2: #endif // BOOST_RANDOM_DISCARD_BLOCK_HPP