1#ifndef BOOST_ARCHIVE_ITERATORS_BINARY_FROM_BASE64_HPP
2#define BOOST_ARCHIVE_ITERATORS_BINARY_FROM_BASE64_HPP
3
4// MS compatible compilers support #pragma once
5#if defined(_MSC_VER)
6# pragma once
7#endif
8
9/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
10// binary_from_base64.hpp
11
12// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
13// Use, modification and distribution is subject to the Boost Software
14// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
15// http://www.boost.org/LICENSE_1_0.txt)
16
17// See http://www.boost.org for updates, documentation, and revision history.
18
19#include <boost/assert.hpp>
20
21#include <boost/serialization/throw_exception.hpp>
22#include <boost/static_assert.hpp>
23
24#include <boost/iterator/transform_iterator.hpp>
25#include <boost/archive/iterators/dataflow_exception.hpp>
26
27namespace boost {
28namespace archive {
29namespace iterators {
30
31/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
32// convert base64 characters to binary data
33
34namespace detail {
35
36template<class CharType>
37struct to_6_bit {
38 typedef CharType result_type;
39 CharType operator()(CharType t) const{
40 static const signed char lookup_table[] = {
41 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
42 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
43 -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63,
44 52,53,54,55,56,57,58,59,60,61,-1,-1,-1, 0,-1,-1, // render '=' as 0
45 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,
46 15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,
47 -1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
48 41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1
49 };
50 // metrowerks trips this assertion - how come?
51 #if ! defined(__MWERKS__)
52 BOOST_STATIC_ASSERT(128 == sizeof(lookup_table));
53 #endif
54 signed char value = -1;
55 if((unsigned)t <= 127)
56 value = lookup_table[(unsigned)t];
57 if(-1 == value)
58 boost::serialization::throw_exception(
59 e: dataflow_exception(dataflow_exception::invalid_base64_character)
60 );
61 return value;
62 }
63};
64
65} // namespace detail
66
67// note: what we would like to do is
68// template<class Base, class CharType = typename Base::value_type>
69// typedef transform_iterator<
70// from_6_bit<CharType>,
71// transform_width<Base, 6, sizeof(Base::value_type) * 8, CharType>
72// > base64_from_binary;
73// but C++ won't accept this. Rather than using a "type generator" and
74// using a different syntax, make a derivation which should be equivalent.
75//
76// Another issue addressed here is that the transform_iterator doesn't have
77// a templated constructor. This makes it incompatible with the dataflow
78// ideal. This is also addressed here.
79
80template<
81 class Base,
82 class CharType = typename boost::iterator_value<Base>::type
83>
84class binary_from_base64 : public
85 transform_iterator<
86 detail::to_6_bit<CharType>,
87 Base
88 >
89{
90 friend class boost::iterator_core_access;
91 typedef transform_iterator<
92 detail::to_6_bit<CharType>,
93 Base
94 > super_t;
95public:
96 // make composable by using templated constructor
97 template<class T>
98 binary_from_base64(T start) :
99 super_t(
100 Base(static_cast< T >(start)),
101 detail::to_6_bit<CharType>()
102 )
103 {}
104 // intel 7.1 doesn't like default copy constructor
105 binary_from_base64(const binary_from_base64 & rhs) :
106 super_t(
107 Base(rhs.base_reference()),
108 detail::to_6_bit<CharType>()
109 )
110 {}
111// binary_from_base64(){};
112};
113
114} // namespace iterators
115} // namespace archive
116} // namespace boost
117
118#endif // BOOST_ARCHIVE_ITERATORS_BINARY_FROM_BASE64_HPP
119

source code of boost/libs/serialization/include/boost/archive/iterators/binary_from_base64.hpp