74 lines
2.0 KiB
Plaintext
74 lines
2.0 KiB
Plaintext
/* 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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* $Id$
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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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