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