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;
operator ++()31   Generator& operator++() { v = cast()(); return cast(); }
operator *() const32   const value_type& operator*() const { return v; }
33 
34 protected:
35   // instantiate from derived classes only
generator_iterator_mixin_adapter()36   generator_iterator_mixin_adapter() { }
iterator_init()37   void iterator_init() { operator++(); }
38 private:
cast()39   Generator & cast() { return static_cast<Generator&>(*this); }
40   value_type v;
41 };
42 
43 } // namespace boost
44 
45 #endif // BOOST_ITERATOR_MIXIN_HPP
46