Implement uniform_inside_sphere_distribution extension.

2016-10-26  Edward Smith-Rowland  <3dw4rd@verizon.net>

	Implement uniform_inside_sphere_distribution extension.
	* include/ext/random: Implement uniform_inside_sphere_distribution.
	* include/ext/random.tcc: Ditto.
	* testsuite/ext/random/uniform_inside_sphere_distribution/
	cons/default.cc: New.
	* testsuite/ext/random/uniform_inside_sphere_distribution/
	cons/parms.cc: New.
	* testsuite/ext/random/uniform_inside_sphere_distribution/
	operators/equal.cc: New.
	* testsuite/ext/random/uniform_inside_sphere_distribution/
	operators/generate.cc: New.
	* testsuite/ext/random/uniform_inside_sphere_distribution/
	operators/inequal.cc: New.
	* testsuite/ext/random/uniform_inside_sphere_distribution/
	operators/serialize.cc: New.

From-SVN: r241562

1 files changed, 212 insertions, 0 deletions

diff --git a/libstdc++-v3/include/ext/random b/libstdc++-v3/include/ext/random
index cdd3ec1..167c560 100644
--- a/libstdc++-v3/include/ext/random
+++ b/libstdc++-v3/include/ext/random
@@ -3493,6 +3493,218 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	       _RealType>& __d2)
     { return !(__d1 == __d2); }
 
+
+  /**
+   * @brief A distribution for random coordinates inside a unit sphere.
+   */
+  template<std::size_t _Dimen, typename _RealType = double>
+    class uniform_inside_sphere_distribution
+    {
+      static_assert(std::is_floating_point<_RealType>::value,
+		    "template argument not a floating point type");
+      static_assert(_Dimen != 0, "dimension is zero");
+
+    public:
+      /** The type of the range of the distribution. */
+      using result_type = std::array<_RealType, _Dimen>;
+
+      /** Parameter type. */
+      struct param_type
+      {
+	using distribution_type
+	  = uniform_inside_sphere_distribution<_Dimen, _RealType>;
+	friend class uniform_inside_sphere_distribution<_Dimen, _RealType>;
+
+	explicit
+	param_type(_RealType __radius = _RealType(1))
+	: _M_radius(__radius)
+	{
+	  __glibcxx_assert(_M_radius > _RealType(0));
+	}
+
+	_RealType
+	radius() const
+	{ return _M_radius; }
+
+	friend bool
+	operator==(const param_type& __p1, const param_type& __p2)
+	{ return __p1._M_radius == __p2._M_radius; }
+
+      private:
+	_RealType _M_radius;
+      };
+
+      /**
+       * @brief Constructors.
+       */
+      explicit
+      uniform_inside_sphere_distribution(_RealType __radius = _RealType(1))
+      : _M_param(__radius), _M_uosd()
+      { }
+
+      explicit
+      uniform_inside_sphere_distribution(const param_type& __p)
+      : _M_param(__p), _M_uosd()
+      { }
+
+      /**
+       * @brief Resets the distribution state.
+       */
+      void
+      reset()
+      { _M_uosd.reset(); }
+
+      /**
+       * @brief Returns the @f$radius@f$ of the distribution.
+       */
+      _RealType
+      radius() const
+      { return _M_param.radius(); }
+
+      /**
+       * @brief Returns the parameter set of the distribution.
+       */
+      param_type
+      param() const
+      { return _M_param; }
+
+      /**
+       * @brief Sets the parameter set of the distribution.
+       * @param __param The new parameter set of the distribution.
+       */
+      void
+      param(const param_type& __param)
+      { _M_param = __param; }
+
+      /**
+       * @brief Returns the greatest lower bound value of the distribution.
+       * This function makes no sense for this distribution.
+       */
+      result_type
+      min() const
+      {
+	result_type __res;
+	__res.fill(0);
+	return __res;
+      }
+
+      /**
+       * @brief Returns the least upper bound value of the distribution.
+       * This function makes no sense for this distribution.
+       */
+      result_type
+      max() const
+      {
+	result_type __res;
+	__res.fill(0);
+	return __res;
+      }
+
+      /**
+       * @brief Generating functions.
+       */
+      template<typename _UniformRandomNumberGenerator>
+	result_type
+	operator()(_UniformRandomNumberGenerator& __urng)
+	{ return this->operator()(__urng, _M_param); }
+
+      template<typename _UniformRandomNumberGenerator>
+	result_type
+	operator()(_UniformRandomNumberGenerator& __urng,
+		   const param_type& __p);
+
+      template<typename _ForwardIterator,
+	       typename _UniformRandomNumberGenerator>
+	void
+	__generate(_ForwardIterator __f, _ForwardIterator __t,
+		   _UniformRandomNumberGenerator& __urng)
+	{ this->__generate(__f, __t, __urng, this->param()); }
+
+      template<typename _ForwardIterator,
+	       typename _UniformRandomNumberGenerator>
+	void
+	__generate(_ForwardIterator __f, _ForwardIterator __t,
+		   _UniformRandomNumberGenerator& __urng,
+		   const param_type& __p)
+	{ this->__generate_impl(__f, __t, __urng, __p); }
+
+      template<typename _UniformRandomNumberGenerator>
+	void
+	__generate(result_type* __f, result_type* __t,
+		   _UniformRandomNumberGenerator& __urng,
+		   const param_type& __p)
+	{ this->__generate_impl(__f, __t, __urng, __p); }
+
+      /**
+       * @brief Return true if two uniform on sphere distributions have
+       *        the same parameters and the sequences that would be
+       *        generated are equal.
+       */
+      friend bool
+      operator==(const uniform_inside_sphere_distribution& __d1,
+		 const uniform_inside_sphere_distribution& __d2)
+      { return __d1._M_param == __d2._M_param && __d1._M_uosd == __d2._M_uosd; }
+
+      /**
+       * @brief Inserts a %uniform_inside_sphere_distribution random number
+       *        distribution @p __x into the output stream @p __os.
+       *
+       * @param __os An output stream.
+       * @param __x  A %uniform_inside_sphere_distribution random number
+       *             distribution.
+       *
+       * @returns The output stream with the state of @p __x inserted or in
+       * an error state.
+       */
+      template<size_t _Dimen1, typename _RealType1, typename _CharT,
+	       typename _Traits>
+	friend std::basic_ostream<_CharT, _Traits>&
+	operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+		   const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen1,
+								   _RealType1>&
+		   );
+
+      /**
+       * @brief Extracts a %uniform_inside_sphere_distribution random number
+       *        distribution
+       * @p __x from the input stream @p __is.
+       *
+       * @param __is An input stream.
+       * @param __x  A %uniform_inside_sphere_distribution random number
+       *             generator engine.
+       *
+       * @returns The input stream with @p __x extracted or in an error state.
+       */
+      template<std::size_t _Dimen1, typename _RealType1, typename _CharT,
+	       typename _Traits>
+	friend std::basic_istream<_CharT, _Traits>&
+	operator>>(std::basic_istream<_CharT, _Traits>& __is,
+		   __gnu_cxx::uniform_inside_sphere_distribution<_Dimen1,
+								 _RealType1>&);
+
+    private:
+      template<typename _ForwardIterator,
+	       typename _UniformRandomNumberGenerator>
+	void
+	__generate_impl(_ForwardIterator __f, _ForwardIterator __t,
+			_UniformRandomNumberGenerator& __urng,
+			const param_type& __p);
+
+      param_type _M_param;
+      uniform_on_sphere_distribution<_Dimen, _RealType> _M_uosd;
+    };
+
+  /**
+   * @brief Return true if two uniform on sphere distributions are different.
+   */
+  template<std::size_t _Dimen, typename _RealType>
+    inline bool
+    operator!=(const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen,
+	       _RealType>& __d1,
+	       const __gnu_cxx::uniform_inside_sphere_distribution<_Dimen,
+	       _RealType>& __d2)
+    { return !(__d1 == __d2); }
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace __gnu_cxx