1// ----------------------------------------------------------------------------
2// alt_sstream.hpp : alternative stringstream
3// ----------------------------------------------------------------------------
4
5// Copyright Samuel Krempp 2003. Use, modification, and distribution are
6// subject to the Boost Software License, Version 1.0. (See accompanying
7// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
8
9// See http://www.boost.org/libs/format for library home page
10
11// ----------------------------------------------------------------------------
12
13
14
15#ifndef BOOST_SK_ALT_SSTREAM_HPP
16#define BOOST_SK_ALT_SSTREAM_HPP
17
18#include <string>
19#include <boost/format/detail/compat_workarounds.hpp>
20#include <boost/utility/base_from_member.hpp>
21#include <boost/shared_ptr.hpp>
22#include <boost/assert.hpp>
23
24namespace boost {
25 namespace io {
26
27 template<class Ch, class Tr=::std::char_traits<Ch>,
28 class Alloc=::std::allocator<Ch> >
29 class basic_altstringbuf;
30
31 template<class Ch, class Tr =::std::char_traits<Ch>,
32 class Alloc=::std::allocator<Ch> >
33 class basic_oaltstringstream;
34
35
36 template<class Ch, class Tr, class Alloc>
37 class basic_altstringbuf
38 : public ::std::basic_streambuf<Ch, Tr>
39 {
40 typedef ::std::basic_streambuf<Ch, Tr> streambuf_t;
41 typedef typename CompatAlloc<Alloc>::compatible_type compat_allocator_type;
42 typedef typename CompatTraits<Tr>::compatible_type compat_traits_type;
43 public:
44 typedef Ch char_type;
45 typedef Tr traits_type;
46 typedef typename compat_traits_type::int_type int_type;
47 typedef typename compat_traits_type::pos_type pos_type;
48 typedef typename compat_traits_type::off_type off_type;
49 typedef Alloc allocator_type;
50 typedef ::std::basic_string<Ch, Tr, Alloc> string_type;
51 typedef typename string_type::size_type size_type;
52
53 typedef ::std::streamsize streamsize;
54
55
56 explicit basic_altstringbuf(std::ios_base::openmode mode
57 = std::ios_base::in | std::ios_base::out)
58 : putend_(NULL), is_allocated_(false), mode_(mode)
59 {}
60 explicit basic_altstringbuf(const string_type& s,
61 ::std::ios_base::openmode mode
62 = ::std::ios_base::in | ::std::ios_base::out)
63 : putend_(NULL), is_allocated_(false), mode_(mode)
64 { dealloc(); str(s); }
65 virtual ~basic_altstringbuf()
66 { dealloc(); }
67 using streambuf_t::pbase;
68 using streambuf_t::pptr;
69 using streambuf_t::epptr;
70 using streambuf_t::eback;
71 using streambuf_t::gptr;
72 using streambuf_t::egptr;
73
74 void clear_buffer();
75 void str(const string_type& s);
76
77 // 0-copy access :
78 Ch * begin() const;
79 size_type size() const;
80 size_type cur_size() const; // stop at current pointer
81 Ch * pend() const // the highest position reached by pptr() since creation
82 { return ((putend_ < pptr()) ? pptr() : putend_); }
83 size_type pcount() const
84 { return static_cast<size_type>( pptr() - pbase()) ;}
85
86 // copy buffer to string :
87 string_type str() const
88 { return string_type(begin(), size()); }
89 string_type cur_str() const
90 { return string_type(begin(), cur_size()); }
91 protected:
92 explicit basic_altstringbuf (basic_altstringbuf * s,
93 ::std::ios_base::openmode mode
94 = ::std::ios_base::in | ::std::ios_base::out)
95 : putend_(NULL), is_allocated_(false), mode_(mode)
96 { dealloc(); str(s); }
97
98 virtual pos_type seekoff(off_type off, ::std::ios_base::seekdir way,
99 ::std::ios_base::openmode which
100 = ::std::ios_base::in | ::std::ios_base::out);
101 virtual pos_type seekpos (pos_type pos,
102 ::std::ios_base::openmode which
103 = ::std::ios_base::in | ::std::ios_base::out);
104 virtual int_type underflow();
105 virtual int_type pbackfail(int_type meta = compat_traits_type::eof());
106 virtual int_type overflow(int_type meta = compat_traits_type::eof());
107 void dealloc();
108 private:
109 enum { alloc_min = 256}; // minimum size of allocations
110
111 Ch *putend_; // remembers (over seeks) the highest value of pptr()
112 bool is_allocated_;
113 ::std::ios_base::openmode mode_;
114 compat_allocator_type alloc_; // the allocator object
115 };
116
117
118// --- class basic_oaltstringstream ----------------------------------------
119 template <class Ch, class Tr, class Alloc>
120 class basic_oaltstringstream
121 : private base_from_member< shared_ptr< basic_altstringbuf< Ch, Tr, Alloc> > >,
122 public ::std::basic_ostream<Ch, Tr>
123 {
124 class No_Op {
125 // used as no-op deleter for (not-owner) shared_pointers
126 public:
127 template<class T>
128 const T & operator()(const T & arg) { return arg; }
129 };
130 typedef ::std::basic_ostream<Ch, Tr> stream_t;
131 typedef boost::base_from_member<boost::shared_ptr<
132 basic_altstringbuf<Ch,Tr, Alloc> > >
133 pbase_type;
134 typedef ::std::basic_string<Ch, Tr, Alloc> string_type;
135 typedef typename string_type::size_type size_type;
136 typedef basic_altstringbuf<Ch, Tr, Alloc> stringbuf_t;
137 public:
138 typedef Alloc allocator_type;
139 basic_oaltstringstream()
140 : pbase_type(new stringbuf_t), stream_t(rdbuf())
141 { }
142 basic_oaltstringstream(::boost::shared_ptr<stringbuf_t> buf)
143 : pbase_type(buf), stream_t(rdbuf())
144 { }
145 basic_oaltstringstream(stringbuf_t * buf)
146 : pbase_type(buf, No_Op() ), stream_t(rdbuf())
147 { }
148 stringbuf_t * rdbuf() const
149 { return pbase_type::member.get(); }
150 void clear_buffer()
151 { rdbuf()->clear_buffer(); }
152
153 // 0-copy access :
154 Ch * begin() const
155 { return rdbuf()->begin(); }
156 size_type size() const
157 { return rdbuf()->size(); }
158 size_type cur_size() const // stops at current position
159 { return rdbuf()->cur_size(); }
160
161 // copy buffer to string :
162 string_type str() const // [pbase, epptr[
163 { return rdbuf()->str(); }
164 string_type cur_str() const // [pbase, pptr[
165 { return rdbuf()->cur_str(); }
166 void str(const string_type& s)
167 { rdbuf()->str(s); }
168 };
169
170 } // N.S. io
171} // N.S. boost
172
173#include <boost/format/alt_sstream_impl.hpp>
174
175#endif // include guard
176
177

source code of boost/boost/format/alt_sstream.hpp