From Jason Turner

[depr.conversions.buffer]

C++14 → C++17 6.8 KB 185 lines
Current Draft | LaTeX Source
Archived: C++14 | C++17
Markdown: C++14 | C++17
Explore in Adventure Game

Diff to HTML by rtfpessoa

Files changed (1) hide show
  1. tmp/tmpyu3ayvg8/{from.md → to.md} +182 -0
tmp/tmpyu3ayvg8/{from.md → to.md} RENAMED
@@ -0,0 +1,182 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ ### Class template `wbuffer_convert` <a id="depr.conversions.buffer">[[depr.conversions.buffer]]</a>
2
+
3
+ Class template `wbuffer_convert` looks like a wide stream buffer, but
4
+ performs all its I/O through an underlying byte stream buffer that you
5
+ specify when you construct it. Like class template `wstring_convert`, it
6
+ lets you specify a code conversion facet to perform the conversions,
7
+ without affecting any streams or locales.
8
+
9
+ ``` cpp
10
+ namespace std {
11
+ template <class Codecvt, class Elem = wchar_t, class Tr = char_traits<Elem>>
12
+ class wbuffer_convert : public basic_streambuf<Elem, Tr> {
13
+ public:
14
+ using state_type = typename Codecvt::state_type;
15
+
16
+ explicit wbuffer_convert(streambuf* bytebuf = 0,
17
+ Codecvt* pcvt = new Codecvt,
18
+ state_type state = state_type());
19
+
20
+ ~wbuffer_convert();
21
+
22
+ wbuffer_convert(const wbuffer_convert&) = delete;
23
+ wbuffer_convert& operator=(const wbuffer_convert&) = delete;
24
+
25
+ streambuf* rdbuf() const;
26
+ streambuf* rdbuf(streambuf* bytebuf);
27
+
28
+ state_type state() const;
29
+
30
+ private:
31
+ streambuf* bufptr; // exposition only
32
+ Codecvt* cvtptr; // exposition only
33
+ state_type cvtstate; // exposition only
34
+ };
35
+ }
36
+ ```
37
+
38
+ The class template describes a stream buffer that controls the
39
+ transmission of elements of type `Elem`, whose character traits are
40
+ described by the class `Tr`, to and from a byte stream buffer of type
41
+ `streambuf`. Conversion between a sequence of `Elem` values and
42
+ multibyte sequences is performed by an object of class `Codecvt`, which
43
+ shall meet the requirements of the standard code-conversion facet
44
+ `codecvt<Elem, char, mbstate_t>`.
45
+
46
+ An object of this class template stores:
47
+
48
+ - `bufptr` — a pointer to its underlying byte stream buffer
49
+ - `cvtptr` — a pointer to the allocated conversion object (which is
50
+ freed when the `wbuffer_convert` object is destroyed)
51
+ - `cvtstate` — a conversion state object
52
+
53
+ ``` cpp
54
+ state_type state() const;
55
+ ```
56
+
57
+ *Returns:* `cvtstate`.
58
+
59
+ ``` cpp
60
+ streambuf* rdbuf() const;
61
+ ```
62
+
63
+ *Returns:* `bufptr`.
64
+
65
+ ``` cpp
66
+ streambuf* rdbuf(streambuf* bytebuf);
67
+ ```
68
+
69
+ *Effects:* Stores `bytebuf` in `bufptr`.
70
+
71
+ *Returns:* The previous value of `bufptr`.
72
+
73
+ ``` cpp
74
+ using state_type = typename Codecvt::state_type;
75
+ ```
76
+
77
+ The type shall be a synonym for `Codecvt::state_type`.
78
+
79
+ ``` cpp
80
+ explicit wbuffer_convert(
81
+ streambuf* bytebuf = 0,
82
+ Codecvt* pcvt = new Codecvt,
83
+ state_type state = state_type());
84
+ ```
85
+
86
+ *Requires:* `pcvt != nullptr`.
87
+
88
+ *Effects:* The constructor constructs a stream buffer object,
89
+ initializes `bufptr` to `bytebuf`, initializes `cvtptr` to `pcvt`, and
90
+ initializes `cvtstate` to `state`.
91
+
92
+ ``` cpp
93
+ ~wbuffer_convert();
94
+ ```
95
+
96
+ *Effects:* The destructor shall delete `cvtptr`.
97
+
98
+ <!-- Link reference definitions -->
99
+ [basic.align]: basic.md#basic.align
100
+ [basic.scope.namespace]: basic.md#basic.scope.namespace
101
+ [basic.types]: basic.md#basic.types
102
+ [class.copy]: special.md#class.copy
103
+ [class.dtor]: special.md#class.dtor
104
+ [cmath.syn]: numerics.md#cmath.syn
105
+ [complex.syn]: numerics.md#complex.syn
106
+ [containers]: containers.md#containers
107
+ [cstddef.syn]: language.md#cstddef.syn
108
+ [dcl.attr.deprecated]: dcl.md#dcl.attr.deprecated
109
+ [dcl.fct.def]: dcl.md#dcl.fct.def
110
+ [default.allocator]: utilities.md#default.allocator
111
+ [depr]: #depr
112
+ [depr.c.headers]: #depr.c.headers
113
+ [depr.ccomplex.syn]: #depr.ccomplex.syn
114
+ [depr.codecvt.syn]: #depr.codecvt.syn
115
+ [depr.conversions]: #depr.conversions
116
+ [depr.conversions.buffer]: #depr.conversions.buffer
117
+ [depr.conversions.string]: #depr.conversions.string
118
+ [depr.cpp.headers]: #depr.cpp.headers
119
+ [depr.cstdalign.syn]: #depr.cstdalign.syn
120
+ [depr.cstdbool.syn]: #depr.cstdbool.syn
121
+ [depr.ctgmath.syn]: #depr.ctgmath.syn
122
+ [depr.default.allocator]: #depr.default.allocator
123
+ [depr.except.spec]: #depr.except.spec
124
+ [depr.func.adaptor.binding]: #depr.func.adaptor.binding
125
+ [depr.func.adaptor.typedefs]: #depr.func.adaptor.typedefs
126
+ [depr.impldec]: #depr.impldec
127
+ [depr.istrstream]: #depr.istrstream
128
+ [depr.istrstream.cons]: #depr.istrstream.cons
129
+ [depr.istrstream.members]: #depr.istrstream.members
130
+ [depr.iterator.basic]: #depr.iterator.basic
131
+ [depr.iterator.primitives]: #depr.iterator.primitives
132
+ [depr.locale.stdcvt]: #depr.locale.stdcvt
133
+ [depr.locale.stdcvt.req]: #depr.locale.stdcvt.req
134
+ [depr.meta.types]: #depr.meta.types
135
+ [depr.negators]: #depr.negators
136
+ [depr.ostrstream]: #depr.ostrstream
137
+ [depr.ostrstream.cons]: #depr.ostrstream.cons
138
+ [depr.ostrstream.members]: #depr.ostrstream.members
139
+ [depr.static_constexpr]: #depr.static_constexpr
140
+ [depr.storage.iterator]: #depr.storage.iterator
141
+ [depr.str.strstreams]: #depr.str.strstreams
142
+ [depr.strstream]: #depr.strstream
143
+ [depr.strstream.cons]: #depr.strstream.cons
144
+ [depr.strstream.dest]: #depr.strstream.dest
145
+ [depr.strstream.oper]: #depr.strstream.oper
146
+ [depr.strstreambuf]: #depr.strstreambuf
147
+ [depr.strstreambuf.cons]: #depr.strstreambuf.cons
148
+ [depr.strstreambuf.members]: #depr.strstreambuf.members
149
+ [depr.strstreambuf.virtuals]: #depr.strstreambuf.virtuals
150
+ [depr.temporary.buffer]: #depr.temporary.buffer
151
+ [depr.uncaught]: #depr.uncaught
152
+ [depr.util.smartptr.shared.obs]: #depr.util.smartptr.shared.obs
153
+ [depr.weak.result_type]: #depr.weak.result_type
154
+ [expr.unary.op]: expr.md#expr.unary.op
155
+ [func.bind.bind]: utilities.md#func.bind.bind
156
+ [func.def]: utilities.md#func.def
157
+ [function.objects]: utilities.md#function.objects
158
+ [meta.rqmts]: utilities.md#meta.rqmts
159
+ [namespace.udecl]: dcl.md#namespace.udecl
160
+ [new.delete]: language.md#new.delete
161
+ [output.iterators]: iterators.md#output.iterators
162
+ [sf.cmath]: numerics.md#sf.cmath
163
+ [support.types.byteops]: language.md#support.types.byteops
164
+ [tab:future.c.headers]: #tab:future.c.headers
165
+ [tab:future.newoff.values]: #tab:future.newoff.values
166
+ [tab:future.seekoff.positioning]: #tab:future.seekoff.positioning
167
+ [tab:future.strstreambuf.effects]: #tab:future.strstreambuf.effects
168
+ [tab:future.strstreambuf1.effects]: #tab:future.strstreambuf1.effects
169
+ [tab:future.strstreambuf2.effects]: #tab:future.strstreambuf2.effects
170
+ [temp.deduct]: temp.md#temp.deduct
171
+ [unord.hash]: utilities.md#unord.hash
172
+ [util.smartptr.shared]: utilities.md#util.smartptr.shared
173
+
174
+ [^1]: The function signature `strlen(const char*)` is declared in
175
+ `<cstring>` ([[cstring.syn]]). The macro `INT_MAX` is defined in
176
+ `<climits>` ([[climits.syn]]).
177
+
178
+ [^2]: An implementation should consider `alsize` in making this
179
+ decision.
180
+
181
+ [^3]: The function signature `strlen(const char*)` is declared in
182
+ `<cstring>` ([[cstring.syn]]).