1 | //----------------------------------------------------------------------------- |
2 | // boost detail/templated_streams.hpp header file |
3 | // See http://www.boost.org for updates, documentation, and revision history. |
4 | //----------------------------------------------------------------------------- |
5 | // |
6 | // Copyright (c) 2013 John Maddock, Antony Polukhin |
7 | // |
8 | // |
9 | // Distributed under the Boost Software License, Version 1.0. (See |
10 | // accompanying file LICENSE_1_0.txt or copy at |
11 | // http://www.boost.org/LICENSE_1_0.txt) |
12 | |
13 | #ifndef BOOST_DETAIL_BASIC_POINTERBUF_HPP |
14 | #define BOOST_DETAIL_BASIC_POINTERBUF_HPP |
15 | |
16 | // MS compatible compilers support #pragma once |
17 | #if defined(_MSC_VER) |
18 | # pragma once |
19 | #endif |
20 | |
21 | #include "boost/config.hpp" |
22 | #include <streambuf> |
23 | |
24 | namespace boost { namespace detail { |
25 | |
26 | // |
27 | // class basic_pointerbuf: |
28 | // acts as a stream buffer which wraps around a pair of pointers: |
29 | // |
30 | template <class charT, class BufferT > |
31 | class basic_pointerbuf : public BufferT { |
32 | protected: |
33 | typedef BufferT base_type; |
34 | typedef basic_pointerbuf<charT, BufferT> this_type; |
35 | typedef typename base_type::int_type int_type; |
36 | typedef typename base_type::char_type char_type; |
37 | typedef typename base_type::pos_type pos_type; |
38 | typedef ::std::streamsize streamsize; |
39 | typedef typename base_type::off_type off_type; |
40 | |
41 | public: |
42 | basic_pointerbuf() : base_type() { this_type::setbuf(s: 0, n: 0); } |
43 | const charT* getnext() { return this->gptr(); } |
44 | |
45 | #ifndef BOOST_NO_USING_TEMPLATE |
46 | using base_type::pptr; |
47 | using base_type::pbase; |
48 | #else |
49 | charT* pptr() const { return base_type::pptr(); } |
50 | charT* pbase() const { return base_type::pbase(); } |
51 | #endif |
52 | |
53 | protected: |
54 | // VC mistakenly assumes that `setbuf` and other functions are not referenced. |
55 | // Marking those functions with `inline` suppresses the warnings. |
56 | // There must be no harm from marking virtual functions as inline: inline virtual |
57 | // call can be inlined ONLY when the compiler knows the "exact class". |
58 | inline base_type* setbuf(char_type* s, streamsize n) BOOST_OVERRIDE; |
59 | inline typename this_type::pos_type seekpos(pos_type sp, ::std::ios_base::openmode which) BOOST_OVERRIDE; |
60 | inline typename this_type::pos_type seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which) BOOST_OVERRIDE; |
61 | |
62 | private: |
63 | basic_pointerbuf& operator=(const basic_pointerbuf&); |
64 | basic_pointerbuf(const basic_pointerbuf&); |
65 | }; |
66 | |
67 | template<class charT, class BufferT> |
68 | BufferT* |
69 | basic_pointerbuf<charT, BufferT>::setbuf(char_type* s, streamsize n) |
70 | { |
71 | this->setg(s, s, s + n); |
72 | return this; |
73 | } |
74 | |
75 | template<class charT, class BufferT> |
76 | typename basic_pointerbuf<charT, BufferT>::pos_type |
77 | basic_pointerbuf<charT, BufferT>::seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which) |
78 | { |
79 | typedef typename boost::int_t<sizeof(way) * CHAR_BIT>::least cast_type; |
80 | |
81 | if(which & ::std::ios_base::out) |
82 | return pos_type(off_type(-1)); |
83 | std::ptrdiff_t size = this->egptr() - this->eback(); |
84 | std::ptrdiff_t pos = this->gptr() - this->eback(); |
85 | charT* g = this->eback(); |
86 | switch(static_cast<cast_type>(way)) |
87 | { |
88 | case ::std::ios_base::beg: |
89 | if((off < 0) || (off > size)) |
90 | return pos_type(off_type(-1)); |
91 | else |
92 | this->setg(g, g + off, g + size); |
93 | break; |
94 | case ::std::ios_base::end: |
95 | if((off < 0) || (off > size)) |
96 | return pos_type(off_type(-1)); |
97 | else |
98 | this->setg(g, g + size - off, g + size); |
99 | break; |
100 | case ::std::ios_base::cur: |
101 | { |
102 | std::ptrdiff_t newpos = static_cast<std::ptrdiff_t>(pos + off); |
103 | if((newpos < 0) || (newpos > size)) |
104 | return pos_type(off_type(-1)); |
105 | else |
106 | this->setg(g, g + newpos, g + size); |
107 | break; |
108 | } |
109 | default: ; |
110 | } |
111 | #ifdef BOOST_MSVC |
112 | #pragma warning(push) |
113 | #pragma warning(disable:4244) |
114 | #endif |
115 | return static_cast<pos_type>(this->gptr() - this->eback()); |
116 | #ifdef BOOST_MSVC |
117 | #pragma warning(pop) |
118 | #endif |
119 | } |
120 | |
121 | template<class charT, class BufferT> |
122 | typename basic_pointerbuf<charT, BufferT>::pos_type |
123 | basic_pointerbuf<charT, BufferT>::seekpos(pos_type sp, ::std::ios_base::openmode which) |
124 | { |
125 | if(which & ::std::ios_base::out) |
126 | return pos_type(off_type(-1)); |
127 | off_type size = static_cast<off_type>(this->egptr() - this->eback()); |
128 | charT* g = this->eback(); |
129 | if(off_type(sp) <= size) |
130 | { |
131 | this->setg(g, g + off_type(sp), g + size); |
132 | } |
133 | return pos_type(off_type(-1)); |
134 | } |
135 | |
136 | }} // namespace boost::detail |
137 | |
138 | #endif // BOOST_DETAIL_BASIC_POINTERBUF_HPP |
139 | |