view release on metacpan or  search on metacpan

src/boost/archive/iterators/transform_width.hpp  view on Meta::CPAN

#ifndef BOOST_ARCHIVE_ITERATORS_TRANSFORM_WIDTH_HPP
#define BOOST_ARCHIVE_ITERATORS_TRANSFORM_WIDTH_HPP

// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif

/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
// transform_width.hpp

// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

//  See http://www.boost.org for updates, documentation, and revision history.

// iterator which takes elements of x bits and returns elements of y bits.
// used to change streams of 8 bit characters into streams of 6 bit characters.
// and vice-versa for implementing base64 encodeing/decoding. Be very careful
// when using and end iterator.  end is only reliable detected when the input
// stream length is some common multiple of x and y.  E.G. Base64 6 bit
// character and 8 bit bytes. Lowest common multiple is 24 => 4 6 bit characters
// or 3 8 bit characters

#include <boost/config.hpp> // for BOOST_DEDUCED_TYPENAME & PTFO
#include <boost/serialization/pfto.hpp>

#include <boost/iterator/iterator_adaptor.hpp>
#include <boost/iterator/iterator_traits.hpp>

namespace boost { 
namespace archive {
namespace iterators {

/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
// class used by text archives to translate char strings to wchar_t
// strings of the currently selected locale
template<
    class Base, 
    int BitsOut, 
    int BitsIn, 
    class CharType = BOOST_DEDUCED_TYPENAME boost::iterator_value<Base>::type // output character
>
class transform_width : 
    public boost::iterator_adaptor<
        transform_width<Base, BitsOut, BitsIn, CharType>,
        Base,
        CharType,
        single_pass_traversal_tag,
        CharType
    >
{
    friend class boost::iterator_core_access;
    typedef BOOST_DEDUCED_TYPENAME boost::iterator_adaptor<
        transform_width<Base, BitsOut, BitsIn, CharType>,
        Base,
        CharType,
        single_pass_traversal_tag,
        CharType
    > super_t;

    typedef transform_width<Base, BitsOut, BitsIn, CharType> this_t;
    typedef BOOST_DEDUCED_TYPENAME iterator_value<Base>::type base_value_type;

    void fill();

    CharType dereference() const {
        if(!m_buffer_out_full)
            const_cast<this_t *>(this)->fill();
        return m_buffer_out;
    }

    bool equal_impl(const this_t & rhs){
        if(BitsIn < BitsOut) // discard any left over bits
            return this->base_reference() == rhs.base_reference();
        else{
            // BitsIn > BitsOut  // zero fill
            if(this->base_reference() == rhs.base_reference()){
                m_end_of_sequence = true;
                return 0 == m_remaining_bits;
            }
            return false;
        }
    }

    // standard iterator interface
    bool equal(const this_t & rhs) const {
        return const_cast<this_t *>(this)->equal_impl(rhs);
    }

    void increment(){
        m_buffer_out_full = false;
    }

    bool m_buffer_out_full;
    CharType m_buffer_out;