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73 lines
2.0 KiB
73 lines
2.0 KiB
/* boost random/random_number_generator.hpp header file |
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* |
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* Copyright Jens Maurer 2000-2001 |
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* Distributed under the Boost Software License, Version 1.0. (See |
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* accompanying file LICENSE_1_0.txt or copy at |
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* http://www.boost.org/LICENSE_1_0.txt) |
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* |
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* See http://www.boost.org for most recent version including documentation. |
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* |
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* $Id: random_number_generator.hpp 71018 2011-04-05 21:27:52Z steven_watanabe $ |
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* |
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* Revision history |
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* 2001-02-18 moved to individual header files |
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*/ |
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#ifndef BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP |
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#define BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP |
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#include <boost/assert.hpp> |
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#include <boost/random/uniform_int_distribution.hpp> |
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#include <boost/random/detail/disable_warnings.hpp> |
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namespace boost { |
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namespace random { |
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/** |
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* Instantiations of class template random_number_generator model a |
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* RandomNumberGenerator (std:25.2.11 [lib.alg.random.shuffle]). On |
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* each invocation, it returns a uniformly distributed integer in |
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* the range [0..n). |
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* |
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* The template parameter IntType shall denote some integer-like value type. |
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*/ |
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template<class URNG, class IntType = long> |
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class random_number_generator |
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{ |
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public: |
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typedef URNG base_type; |
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typedef IntType argument_type; |
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typedef IntType result_type; |
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/** |
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* Constructs a random_number_generator functor with the given |
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* \uniform_random_number_generator as the underlying source of |
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* random numbers. |
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*/ |
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random_number_generator(base_type& rng) : _rng(rng) {} |
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// compiler-generated copy ctor is fine |
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// assignment is disallowed because there is a reference member |
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/** |
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* Returns a value in the range [0, n) |
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*/ |
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result_type operator()(argument_type n) |
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{ |
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BOOST_ASSERT(n > 0); |
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return uniform_int_distribution<IntType>(0, n-1)(_rng); |
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} |
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private: |
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base_type& _rng; |
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}; |
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} // namespace random |
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using random::random_number_generator; |
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} // namespace boost |
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#include <boost/random/detail/enable_warnings.hpp> |
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#endif // BOOST_RANDOM_RANDOM_NUMBER_GENERATOR_HPP
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