Chris@16: #ifndef BOOST_ARCHIVE_ITERATORS_HEAD_ITERATOR_HPP
Chris@16: #define BOOST_ARCHIVE_ITERATORS_HEAD_ITERATOR_HPP
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
Chris@16: // head_iterator.hpp
Chris@16: 
Chris@16: // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 
Chris@16: // Use, modification and distribution is subject to the Boost Software
Chris@16: // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: //  See http://www.boost.org for updates, documentation, and revision history.
Chris@16: 
Chris@16: #include <boost/iterator/iterator_adaptor.hpp>
Chris@16: #include <boost/iterator/iterator_traits.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace archive {
Chris@16: namespace iterators {
Chris@16: 
Chris@16: template<class Predicate, class Base>
Chris@16: class head_iterator
Chris@16:     : public boost::iterator_adaptor<
Chris@16:         head_iterator<Predicate, Base>,
Chris@16:         Base,
Chris@16:         use_default,
Chris@16:         single_pass_traversal_tag
Chris@16:     >
Chris@16: {
Chris@16: private:
Chris@16:     friend class iterator_core_access;
Chris@16:     typedef boost::iterator_adaptor<
Chris@16:         head_iterator<Predicate, Base>,
Chris@16:         Base,
Chris@16:         use_default,
Chris@16:         single_pass_traversal_tag
Chris@16:     > super_t;
Chris@16: 
Chris@16:     typedef head_iterator<Predicate, Base> this_t;
Chris@16:     typedef super_t::value_type value_type;
Chris@16:     typedef super_t::reference reference_type;
Chris@16: 
Chris@16:     reference_type dereference_impl(){
Chris@16:         if(! m_end){
Chris@16:             while(! m_predicate(* this->base_reference()))
Chris@16:                 ++ this->base_reference();
Chris@16:             m_end = true;
Chris@16:         }
Chris@16:         return * this->base_reference();
Chris@16:     }
Chris@16: 
Chris@16:     reference_type dereference() const {
Chris@16:         return const_cast<this_t *>(this)->dereference_impl();
Chris@16:     }
Chris@16: 
Chris@16:     void increment(){
Chris@16:         ++base_reference();
Chris@16:     }
Chris@16:     Predicate m_predicate;
Chris@16:     bool m_end;
Chris@16: public:
Chris@16:     template<class T>
Chris@16:     head_iterator(Predicate f, T start) : 
Chris@16:         super_t(Base(start)), 
Chris@16:         m_predicate(f),
Chris@16:         m_end(false)
Chris@16:     {}
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: } // namespace iterators
Chris@16: } // namespace archive
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_ARCHIVE_ITERATORS_HEAD_ITERATOR_HPP