[Boost-commit] svn:boost r68658 - trunk/boost/random

Subject: [Boost-commit] svn:boost r68658 - trunk/boost/random
From: steven_at_[hidden]
Date: 2011-02-05 12:44:46

Author: steven_watanabe
Date: 2011-02-05 12:44:40 EST (Sat, 05 Feb 2011)
New Revision: 68658
URL: http://svn.boost.org/trac/boost/changeset/68658

Log:
Simplify variate_generator.
Text files modified: 
   trunk/boost/random/cauchy_distribution.hpp |     4                                         
   trunk/boost/random/variate_generator.hpp   |   214 +++++++++++---------------------------- 
   2 files changed, 63 insertions(+), 155 deletions(-)

Modified: trunk/boost/random/cauchy_distribution.hpp
==============================================================================
--- trunk/boost/random/cauchy_distribution.hpp	(original)
+++ trunk/boost/random/cauchy_distribution.hpp	2011-02-05 12:44:40 EST (Sat, 05 Feb 2011)
@@ -22,6 +22,7 @@
 #include <boost/limits.hpp>
 #include <boost/random/detail/config.hpp>
 #include <boost/random/detail/operators.hpp>
+#include <boost/random/uniform_01.hpp>
 
 namespace boost {
 namespace random {
@@ -154,7 +155,8 @@
         // Can we have a boost::mathconst please?
         const result_type pi = result_type(3.14159265358979323846);
         using std::tan;
-        return _median + _sigma * tan(pi*(eng()-result_type(0.5)));
+        RealType val = uniform_01<RealType>()(eng)-result_type(0.5);
+        return _median + _sigma * tan(pi*val);
     }
 
     /**

Modified: trunk/boost/random/variate_generator.hpp
==============================================================================
--- trunk/boost/random/variate_generator.hpp	(original)
+++ trunk/boost/random/variate_generator.hpp	2011-02-05 12:44:40 EST (Sat, 05 Feb 2011)
@@ -1,6 +1,7 @@
 /* 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)
@@ -14,20 +15,7 @@
 #ifndef BOOST_RANDOM_RANDOM_GENERATOR_HPP
 #define BOOST_RANDOM_RANDOM_GENERATOR_HPP
 
-#include <boost/config.hpp>
-
-// implementation details
-#include <boost/detail/workaround.hpp>
-#include <boost/random/uniform_01.hpp>
 #include <boost/random/detail/pass_through_engine.hpp>
-#include <boost/random/detail/uniform_int_float.hpp>
-#include <boost/random/detail/ptr_helper.hpp>
-
-// Borland C++ 5.6.0 has problems using its numeric_limits traits as
-// template parameters
-#if BOOST_WORKAROUND(__BORLANDC__, <= 0x564)
-#include <boost/type_traits/is_integral.hpp>
-#endif
 
 #include <boost/random/detail/disable_warnings.hpp>
 
@@ -36,54 +24,6 @@
 /// \cond hide_private_members
 
 namespace random {
-namespace detail {
-
-template<bool have_int, bool want_int>
-struct engine_helper;
-
-// for consistency, always have two levels of decorations
-template<>
-struct engine_helper<true, true>
-{
-  template<class Engine, class DistInputType>
-  struct impl
-  {
-    typedef pass_through_engine<Engine> type;
-  };
-};
-
-template<>
-struct engine_helper<false, false>
-{
-  template<class Engine, class DistInputType>
-  struct impl
-  {
-    typedef uniform_01<Engine, DistInputType> type;
-  };
-};
-
-template<>
-struct engine_helper<true, false>
-{
-  template<class Engine, class DistInputType>
-  struct impl
-  {
-    typedef uniform_01<Engine, DistInputType> type;
-  };
-};
-
-template<>
-struct engine_helper<false, true>
-{
-  template<class Engine, class DistInputType>
-  struct impl
-  {
-    typedef uniform_int_float<Engine, unsigned long> type;
-  };
-};
-
-} // namespace detail
-} // namespace random
 
 ///\endcond
 
@@ -114,105 +54,71 @@
 class variate_generator
 {
 private:
-  typedef random::detail::pass_through_engine<Engine> decorated_engine;
+    typedef random::detail::pass_through_engine<Engine> decorated_engine;
 
 public:
-  typedef typename decorated_engine::base_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(decorated_engine(e)), _dist(d) { }
-
-  /**
-   * Returns: distribution()(e)
-   *
-   * Notes: The sequence of numbers produced by the
-   * \uniform_random_number_generator e, s<sub>e</sub>, is
-   * obtained from the sequence of numbers produced by the
-   * associated \uniform_random_number_generator eng, s<sub>eng</sub>,
-   * as follows: Consider the values of @c numeric_limits<T>::is_integer
-   * for @c T both @c Distribution::input_type and
-   * @c engine_value_type::result_type. If the values for both types are
-   * true, then se is identical to s<sub>eng</sub>. Otherwise, if the
-   * values for both types are false, then the numbers in s<sub>eng</sub>
-   * are divided by engine().max()-engine().min() to obtain the numbers
-   * in s<sub>e</sub>. Otherwise, if the value for
-   * @c engine_value_type::result_type is true and the value for
-   * @c Distribution::input_type is false, then the numbers in s<sub>eng</sub>
-   * are divided by engine().max()-engine().min()+1 to obtain the numbers in
-   * s<sub>e</sub>. Otherwise, the mapping from s<sub>eng</sub> to
-   * s<sub>e</sub> is implementation-defined. In all cases, an
-   * implicit conversion from @c engine_value_type::result_type to
-   * @c Distribution::input_type is performed. If such a conversion does
-   * not exist, the program is ill-formed.
-   */
-  result_type operator()() { return _dist(_eng); }
-  /**
-   * Returns: distribution()(e, value).
-   * For the semantics of e, see the description of operator()().
-   */
-  template<class T>
-  result_type operator()(T value) { return _dist(_eng, value); }
-
-  /**
-   * Returns: A reference to the associated uniform random number generator.
-   */
-  engine_value_type& engine() { return _eng.base().base(); }
-  /**
-   * Returns: A reference to the associated uniform random number generator.
-   */
-  const engine_value_type& engine() const { return _eng.base().base(); }
-
-  /**
-   * 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)(); }
+    typedef typename decorated_engine::base_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(_eng.base()); }
+    /**
+     * Returns: distribution()(engine(), value).
+     */
+    template<class T>
+    result_type operator()(const T& value) { return _dist(_eng, value); }
+
+    /**
+     * Returns: A reference to the associated uniform random number generator.
+     */
+    engine_value_type& engine() { return _eng.base(); }
+    /**
+     * Returns: A reference to the associated uniform random number generator.
+     */
+    const engine_value_type& engine() const { return _eng.base(); }
+
+    /** 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:
-#if BOOST_WORKAROUND(__BORLANDC__, <= 0x564)
-  typedef typename random::detail::engine_helper<
-    ::boost::is_integral<typename decorated_engine::result_type>::value,
-    ::boost::is_integral<typename Distribution::input_type>::value
-    >::BOOST_NESTED_TEMPLATE impl<decorated_engine, typename Distribution::input_type>::type internal_engine_type;
-#else
-  enum {
-    have_int = std::numeric_limits<typename decorated_engine::result_type>::is_integer,
-    want_int = std::numeric_limits<typename Distribution::input_type>::is_integer
-  };
-  typedef typename random::detail::engine_helper<have_int, want_int>::BOOST_NESTED_TEMPLATE impl<decorated_engine, typename Distribution::input_type>::type internal_engine_type;
-#endif
-
-  internal_engine_type _eng;
-  distribution_type _dist;
+    decorated_engine _eng;
+    distribution_type _dist;
 };
 
+} // namespace random
+
+using random::variate_generator;
+
 } // namespace boost
 
 #include <boost/random/detail/enable_warnings.hpp>