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/core/allocator_access.hpp>
20#include <boost/format/detail/compat_workarounds.hpp>
21#include <boost/utility/base_from_member.hpp>
22#include <boost/shared_ptr.hpp>
23#include <boost/config.hpp>
24#include <boost/assert.hpp>
25
26namespace boost {
27 namespace io {
28
29 template<class Ch, class Tr=::std::char_traits<Ch>,
30 class Alloc=::std::allocator<Ch> >
31 class basic_altstringbuf;
32
33 template<class Ch, class Tr =::std::char_traits<Ch>,
34 class Alloc=::std::allocator<Ch> >
35 class basic_oaltstringstream;
36
37
38 template<class Ch, class Tr, class Alloc>
39 class basic_altstringbuf
40 : public ::std::basic_streambuf<Ch, Tr>
41 {
42 typedef ::std::basic_streambuf<Ch, Tr> streambuf_t;
43 typedef typename CompatAlloc<Alloc>::compatible_type compat_allocator_type;
44 typedef typename CompatTraits<Tr>::compatible_type compat_traits_type;
45 public:
46 typedef Ch char_type;
47 typedef Tr traits_type;
48 typedef typename compat_traits_type::int_type int_type;
49 typedef typename compat_traits_type::pos_type pos_type;
50 typedef typename compat_traits_type::off_type off_type;
51 typedef Alloc allocator_type;
52 typedef ::std::basic_string<Ch, Tr, Alloc> string_type;
53 typedef typename string_type::size_type size_type;
54
55 typedef ::std::streamsize streamsize;
56
57
58 explicit basic_altstringbuf(std::ios_base::openmode mode
59 = std::ios_base::in | std::ios_base::out)
60 : putend_(NULL), is_allocated_(false), mode_(mode)
61 {}
62 explicit basic_altstringbuf(const string_type& s,
63 ::std::ios_base::openmode mode
64 = ::std::ios_base::in | ::std::ios_base::out)
65 : putend_(NULL), is_allocated_(false), mode_(mode)
66 { dealloc(); str(s); }
67 virtual ~basic_altstringbuf() BOOST_NOEXCEPT_OR_NOTHROW
68 { dealloc(); }
69 using streambuf_t::pbase;
70 using streambuf_t::pptr;
71 using streambuf_t::epptr;
72 using streambuf_t::eback;
73 using streambuf_t::gptr;
74 using streambuf_t::egptr;
75
76 void clear_buffer();
77 void str(const string_type& s);
78
79 // 0-copy access :
80 Ch * begin() const;
81 size_type size() const;
82 size_type cur_size() const; // stop at current pointer
83 Ch * pend() const // the highest position reached by pptr() since creation
84 { return ((putend_ < pptr()) ? pptr() : putend_); }
85 size_type pcount() const
86 { return static_cast<size_type>( pptr() - pbase()) ;}
87
88 // copy buffer to string :
89 string_type str() const
90 { return string_type(begin(), size()); }
91 string_type cur_str() const
92 { return string_type(begin(), cur_size()); }
93 protected:
94 explicit basic_altstringbuf (basic_altstringbuf * s,
95 ::std::ios_base::openmode mode
96 = ::std::ios_base::in | ::std::ios_base::out)
97 : putend_(NULL), is_allocated_(false), mode_(mode)
98 { dealloc(); str(s); }
99
100 virtual pos_type seekoff(off_type off, ::std::ios_base::seekdir way,
101 ::std::ios_base::openmode which
102 = ::std::ios_base::in | ::std::ios_base::out);
103 virtual pos_type seekpos (pos_type pos,
104 ::std::ios_base::openmode which
105 = ::std::ios_base::in | ::std::ios_base::out);
106 virtual int_type underflow();
107 virtual int_type pbackfail(int_type meta = compat_traits_type::eof());
108 virtual int_type overflow(int_type meta = compat_traits_type::eof());
109 void dealloc();
110 private:
111 enum { alloc_min = 256}; // minimum size of allocations
112
113 Ch *putend_; // remembers (over seeks) the highest value of pptr()
114 bool is_allocated_;
115 ::std::ios_base::openmode mode_;
116 compat_allocator_type alloc_; // the allocator object
117 };
118
119
120// --- class basic_oaltstringstream ----------------------------------------
121 template <class Ch, class Tr, class Alloc>
122 class basic_oaltstringstream
123 : private base_from_member< shared_ptr< basic_altstringbuf< Ch, Tr, Alloc> > >,
124 public ::std::basic_ostream<Ch, Tr>
125 {
126 class No_Op {
127 // used as no-op deleter for (not-owner) shared_pointers
128 public:
129 template<class T>
130 const T & operator()(const T & arg) { return arg; }
131 };
132 typedef ::std::basic_ostream<Ch, Tr> stream_t;
133 typedef boost::base_from_member<boost::shared_ptr<
134 basic_altstringbuf<Ch,Tr, Alloc> > >
135 pbase_type;
136 typedef ::std::basic_string<Ch, Tr, Alloc> string_type;
137 typedef typename string_type::size_type size_type;
138 typedef basic_altstringbuf<Ch, Tr, Alloc> stringbuf_t;
139 public:
140 typedef Alloc allocator_type;
141 basic_oaltstringstream()
142 : pbase_type(new stringbuf_t), stream_t(pbase_type::member.get())
143 { }
144 basic_oaltstringstream(::boost::shared_ptr<stringbuf_t> buf)
145 : pbase_type(buf), stream_t(pbase_type::member.get())
146 { }
147 basic_oaltstringstream(stringbuf_t * buf)
148 : pbase_type(buf, No_Op() ), stream_t(pbase_type::member.get())
149 { }
150 stringbuf_t * rdbuf() const
151 { return pbase_type::member.get(); }
152 void clear_buffer()
153 { rdbuf()->clear_buffer(); }
154
155 // 0-copy access :
156 Ch * begin() const
157 { return rdbuf()->begin(); }
158 size_type size() const
159 { return rdbuf()->size(); }
160 size_type cur_size() const // stops at current position
161 { return rdbuf()->cur_size(); }
162
163 // copy buffer to string :
164 string_type str() const // [pbase, epptr[
165 { return rdbuf()->str(); }
166 string_type cur_str() const // [pbase, pptr[
167 { return rdbuf()->cur_str(); }
168 void str(const string_type& s)
169 { rdbuf()->str(s); }
170 };
171
172 } // N.S. io
173} // N.S. boost
174
175#include <boost/format/alt_sstream_impl.hpp>
176
177#endif // include guard
178
179

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