Chris@16: #ifndef BOOST_ARCHIVE_ITERATORS_DATAFLOW_HPP
Chris@16: #define BOOST_ARCHIVE_ITERATORS_DATAFLOW_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: // dataflow.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/assert.hpp>
Chris@16: 
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/apply.hpp>
Chris@16: #include <boost/mpl/plus.hpp>
Chris@16: #include <boost/mpl/int.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/is_convertible.hpp>
Chris@16: #include <boost/type_traits/is_base_and_derived.hpp>
Chris@16: #include <boost/type_traits/is_pointer.hpp>
Chris@16: #include <boost/iterator/iterator_adaptor.hpp>
Chris@16: #include <boost/iterator/iterator_traits.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: 
Chris@16: namespace boost { 
Chris@16: namespace archive {
Chris@16: namespace iterators {
Chris@16: 
Chris@16: // poor man's tri-state
Chris@16: struct tri_state {
Chris@16:     enum state_enum {
Chris@16:         is_false = false,
Chris@16:         is_true = true,
Chris@16:         is_indeterminant
Chris@16:     } m_state;
Chris@16:     // convert to bool
Chris@16:     operator bool (){
Chris@16:         BOOST_ASSERT(is_indeterminant != m_state);
Chris@16:         return is_true == m_state ? true : false;
Chris@16:     }
Chris@16:     // assign from bool
Chris@16:     tri_state & operator=(bool rhs) {
Chris@16:         m_state = rhs ? is_true : is_false;
Chris@16:         return *this;
Chris@16:     }
Chris@16:     tri_state(bool rhs) :
Chris@16:         m_state(rhs ? is_true : is_false)
Chris@16:     {}
Chris@16:     tri_state(state_enum state) :
Chris@16:         m_state(state)
Chris@16:     {}
Chris@16:     bool operator==(const tri_state & rhs) const {
Chris@16:         return m_state == rhs.m_state;
Chris@16:     }
Chris@16:     bool operator!=(const tri_state & rhs) const {
Chris@16:         return m_state != rhs.m_state;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
Chris@16: // implement functions common to dataflow iterators
Chris@16: template<class Derived>
Chris@16: class dataflow {
Chris@16:     bool m_eoi;
Chris@16: protected:
Chris@16:     // test for iterator equality
Chris@16:     tri_state equal(const Derived & rhs) const {
Chris@16:         if(m_eoi && rhs.m_eoi)
Chris@16:             return true;
Chris@16:         if(m_eoi || rhs.m_eoi)
Chris@16:             return false;
Chris@16:         return tri_state(tri_state::is_indeterminant);
Chris@16:     }
Chris@16:     void eoi(bool tf){
Chris@16:         m_eoi = tf;
Chris@16:     }
Chris@16:     bool eoi() const {
Chris@16:         return m_eoi;
Chris@16:     }
Chris@16: public:
Chris@16:     dataflow(bool tf) :
Chris@16:         m_eoi(tf)
Chris@16:     {}
Chris@16:     dataflow() : // used for iterator end
Chris@16:         m_eoi(true)
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_DATAFLOW_HPP