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/* boost random/variate_generator.hpp header file

 *

 * Copyright Jens Maurer 2002

 * Copyright Steven Watanabe 2011

 * Distributed under the Boost Software License, Version 1.0. (See

 * accompanying file LICENSE_1_0.txt or copy at

 * http://www.boost.org/LICENSE_1_0.txt)

 *

 * See http://www.boost.org for most recent version including documentation.

 *

 * $Id$

 *

 */

#ifndef BOOST_RANDOM_RANDOM_GENERATOR_HPP

#define BOOST_RANDOM_RANDOM_GENERATOR_HPP


#include <boost/random/detail/ptr_helper.hpp>


#include <boost/random/detail/disable_warnings.hpp>


namespace boost {

/// \cond hide_private_members


namespace random {

///\endcond


/**

 * A random variate generator is used to join a random number

 * generator together with a random number distribution.

 * Boost.Random provides a vast choice of \generators as well

 * as \distributions.

 *

 * The argument for the template parameter Engine shall be of

 * the form U, U&, or U*, where U models a

 * \uniform_random_number_generator.  Then, the member

 * engine_value_type names U (not the pointer or reference to U).

 *

 * Specializations of @c variate_generator satisfy the

 * requirements of CopyConstructible. They also satisfy the

 * requirements of Assignable unless the template parameter

 * Engine is of the form U&.

 *

 * The complexity of all functions specified in this section

 * is constant. No function described in this section except

 * the constructor throws an exception.

 */
template<class Engine, class Distribution>
class variate_generator
{
private:
    typedef boost::random::detail::ptr_helper<Engine> helper_type;
public:
    typedef typename helper_type::value_type engine_value_type;
    typedef Engine engine_type;
    typedef Distribution distribution_type;
    typedef typename Distribution::result_type result_type;

    /**

     * Constructs a @c variate_generator object with the associated

     * \uniform_random_number_generator eng and the associated

     * \random_distribution d.

     *

     * Throws: If and what the copy constructor of Engine or

     * Distribution throws.

     */
    variate_generator(Engine e, Distribution d)
      : _eng(e), _dist(d) { }

    /** Returns: distribution()(engine()) */
    result_type operator()() { return _dist(engine()); }
    /**

     * Returns: distribution()(engine(), value).

     */
    template<class T>
    result_type operator()(const T& value) { return _dist(engine(), value); }

    /**

     * Returns: A reference to the associated uniform random number generator.

     */
    engine_value_type& engine() { return helper_type::ref(_eng); }
    /**

     * Returns: A reference to the associated uniform random number generator.

     */
    const engine_value_type& engine() const { return helper_type::ref(_eng); }

    /** Returns: A reference to the associated \random_distribution. */
    distribution_type& distribution() { return _dist; }
    /**

     * Returns: A reference to the associated random distribution.

     */
    const distribution_type& distribution() const { return _dist; }

    /**

     * Precondition: distribution().min() is well-formed

     *

     * Returns: distribution().min()

     */
    result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (distribution().min)(); }
    /**

     * Precondition: distribution().max() is well-formed

     *

     * Returns: distribution().max()

     */
    result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const { return (distribution().max)(); }

private:
    Engine _eng;
    distribution_type _dist;
};

} // namespace random


using random::variate_generator;

} // namespace boost


#include <boost/random/detail/enable_warnings.hpp>


#endif // BOOST_RANDOM_RANDOM_GENERATOR_HPP