ceph/src/boost/libs/random/include/boost/random/detail/iterator_mixin.hpp

   1 /* boost random/detail/iterator_mixin.hpp header file
   2  *
   3  * Copyright Jens Maurer 2000-2001
   4  * Distributed under the Boost Software License, Version 1.0. (See
   5  * accompanying file LICENSE_1_0.txt or copy at
   6  * http://www.boost.org/LICENSE_1_0.txt)
   7  *
   8  * See http://www.boost.org for most recent version including documentation.
   9  *
  10  * Revision history
  11  */
  12
  13 #ifndef BOOST_ITERATOR_MIXIN_HPP
  14 #define BOOST_ITERATOR_MIXIN_HPP
  15
  16 #include <boost/operators.hpp>
  17
  18 namespace boost {
  19
  20 // must be in boost namespace, otherwise the inline friend trick fails
  21 template<class Generator, class ResultType>
  22 class generator_iterator_mixin_adapter
  23   : incrementable<Generator>, equality_comparable<Generator>
  24 {
  25 public:
  26   typedef std::input_iterator_tag iterator_category;
  27   typedef ResultType value_type;
  28   typedef std::ptrdiff_t difference_type;
  29   typedef const value_type * pointer;
  30   typedef const value_type & reference;
  31   Generator& operator++() { v = cast()(); return cast(); }
  32   const value_type& operator*() const { return v; }
  33
  34 protected:
  35   // instantiate from derived classes only
  36   generator_iterator_mixin_adapter() { }
  37   void iterator_init() { operator++(); }
  38 private:
  39   Generator & cast() { return static_cast<Generator&>(*this); }
  40   value_type v;
  41 };
  42
  43 } // namespace boost
  44
  45 #endif // BOOST_ITERATOR_MIXIN_HPP