1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
|
<HTML>
<!--
-- Copyright (c) 1996-1999
-- Silicon Graphics Computer Systems, Inc.
--
-- Permission to use, copy, modify, distribute and sell this software
-- and its documentation for any purpose is hereby granted without fee,
-- provided that the above copyright notice appears in all copies and
-- that both that copyright notice and this permission notice appear
-- in supporting documentation. Silicon Graphics makes no
-- representations about the suitability of this software for any
-- purpose. It is provided "as is" without express or implied warranty.
--
-- Copyright (c) 1994
-- Hewlett-Packard Company
--
-- Permission to use, copy, modify, distribute and sell this software
-- and its documentation for any purpose is hereby granted without fee,
-- provided that the above copyright notice appears in all copies and
-- that both that copyright notice and this permission notice appear
-- in supporting documentation. Hewlett-Packard Company makes no
-- representations about the suitability of this software for any
-- purpose. It is provided "as is" without express or implied warranty.
--
-->
<Head>
<Title>front_insert_iterator<FrontInsertionSequence></Title>
<!-- Generated by htmldoc -->
</HEAD>
<BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b"
ALINK="#ff0000">
<IMG SRC="CorpID.gif"
ALT="SGI" HEIGHT="43" WIDTH="151">
<!--end header-->
<BR Clear>
<H1>front_insert_iterator<FrontInsertionSequence></H1>
<Table CellPadding=0 CellSpacing=0 width=100%>
<TR>
<TD Align=left><Img src = "iterators.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD>
<TD Align=right><Img src = "type.gif" Alt="" WIDTH = "194" HEIGHT = "39" ></TD>
</TR>
<TR>
<TD Align=left><Img src = "adaptors.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD>
<TD Align=right></TD>
</TR>
<TR>
<TD Align=left VAlign=top><b>Categories</b>: iterators, adaptors</TD>
<TD Align=right VAlign=top><b>Component type</b>: type</TD>
</TR>
</Table>
<h3>Description</h3>
<tt>Front_insert_iterator</tt> is an iterator adaptor that functions as an
<A href="OutputIterator.html">Output Iterator</A>: assignment through a <tt>front_insert_iterator</tt> inserts
an object before the first element of a <A href="FrontInsertionSequence.html">Front Insertion Sequence</A>. <A href="#1">[1]</A> <A href="#2">[2]</A>
<h3>Example</h3>
<pre>
<A href="List.html">list</A><int> L;
L.push_front(3);
front_insert_iterator<<A href="List.html">list</A><int> > ii(L);
*ii++ = 0;
*ii++ = 1;
*ii++ = 2;
<A href="copy.html">copy</A>(L.begin(), L.end(), <A href="ostream_iterator.html">ostream_iterator</A><int>(cout, " "));
// The values that are printed are 2 1 0 3
</pre>
<h3>Definition</h3>
Defined in the standard header <A href="iterator">iterator</A>, and in the nonstandard
backward-compatibility header <A href="iterator.h">iterator.h</A>.
<h3>Template parameters</h3>
<Table border>
<TR>
<TH>
Parameter
</TH>
<TH>
Description
</TH>
<TH>
Default
</TH>
</TR>
<TR>
<TD VAlign=top>
<tt>FrontInsertionSequence</tt>
</TD>
<TD VAlign=top>
The type of <A href="FrontInsertionSequence.html">Front Insertion Sequence</A> into which values will be inserted.
</TD>
<TD VAlign=top>
</TD>
</tr>
</table>
<h3>Model of</h3>
<A href="OutputIterator.html">Output Iterator</A>. A front insert iterator's set of value types (as
defined in the <A href="OutputIterator.html">Output Iterator</A> requirements) consists of
a single type: <tt><A href="FrontInsertionSequence.html">FrontInsertionSequence</A>::value_type</tt>.
<h3>Type requirements</h3>
The template parameter <tt>FrontInsertionSequence</tt> must be a
<A href="FrontInsertionSequence.html">Front Insertion Sequence</A>.
<h3>Public base classes</h3>
None.
<h3>Members</h3>
<Table border>
<TR>
<TH>
Member
</TH>
<TH>
Where defined
</TH>
<TH>
Description
</TH>
</TR>
<TR>
<TD VAlign=top>
<tt><b>front_insert_iterator</b>(FrontInsertionSequence&)</tt>
</TD>
<TD VAlign=top>
<tt>front_insert_iterator</tt>
</TD>
<TD VAlign=top>
See below.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt><b>front_insert_iterator</b>(const front_insert_iterator&)</tt>
</TD>
<TD VAlign=top>
<A href="trivial.html">Trivial Iterator</A>
</TD>
<TD VAlign=top>
The copy constructor
</TD>
</TR>
<TR>
<TD VAlign=top>
<pre>
front_insert_iterator&
<b>operator=</b>(const front_insert_iterator&)
</pre>
</TD>
<TD VAlign=top>
<A href="trivial.html">Trivial Iterator</A>
</TD>
<TD VAlign=top>
The assignment operator
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>front_insert_iterator& <b>operator*</b>()</tt>
</TD>
<TD VAlign=top>
<A href="OutputIterator.html">Output Iterator</A>
</TD>
<TD VAlign=top>
Used to implement the <A href="OutputIterator.html">output iterator</A> expression <tt>*i = x</tt>. <A href="#3">[3]</A>
</TD>
</TR>
<TR>
<TD VAlign=top>
<pre>
front_insert_iterator&
<b>operator=</b>(const FrontInsertionSequence::value_type&)
</pre>
</TD>
<TD VAlign=top>
<A href="OutputIterator.html">Output Iterator</A>
</TD>
<TD VAlign=top>
Used to implement the <A href="OutputIterator.html">output iterator</A> expression <tt>*i = x</tt>. <A href="#3">[3]</A>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>front_insert_iterator& <b>operator++</b>()</tt>
</TD>
<TD VAlign=top>
<A href="OutputIterator.html">Output Iterator</A>
</TD>
<TD VAlign=top>
Preincrement.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>front_insert_iterator& <b>operator++</b>(int)</tt>
</TD>
<TD VAlign=top>
<A href="OutputIterator.html">Output Iterator</A>
</TD>
<TD VAlign=top>
Postincrement.
</TD>
</TR>
<TR>
<TD VAlign=top>
<pre>
output_iterator_tag
<b>iterator_category</b>(const front_insert_iterator&)
</pre>
</TD>
<TD VAlign=top>
<A href="iterator_tags.html">iterator tags</A>
</TD>
<TD VAlign=top>
Returns the iterator's category.
This is a global function, not a member.
</TD>
</TR>
<TR>
<TD VAlign=top>
<pre>
template<class FrontInsertionSequence>
front_insert_iterator<FrontInsertionSequence>
<B>front_inserter</b>(FrontInsertionSequence& S)
</pre>
</TD>
<TD VAlign=top>
<tt>front_insert_iterator</tt>
</TD>
<TD VAlign=top>
See below.
</TD>
</tr>
</table>
<h3>New members.</h3>
These members are not defined
in the <A href="OutputIterator.html">Output Iterator</A> requirements,
but are specific to <tt>front_insert_iterator</tt>.
<Table border>
<TR>
<TH>
Member
</TH>
<TH>
Description
</TH>
</TR>
<TR>
<TD VAlign=top>
<tt><b>front_insert_iterator</b>(FrontInsertionSequence& S)</tt>
</TD>
<TD VAlign=top>
Constructs a <tt>front_insert_iterator</tt> that inserts objects
before the first element of <tt>S</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<pre>
template<class FrontInsertionSequence>
front_insert_iterator<FrontInsertionSequence>
<b>front_inserter</b>(FrontInsertionSequence& S);
</pre>
</TD>
<TD VAlign=top>
Equivalent to <tt>front_insert_iterator<FrontInsertionSequence>(S)</tt>. <A href="#4">[4]</A>
This is a global function, not a member function.
</TD>
</tr>
</table>
<h3>Notes</h3>
<P><A name="1">[1]</A>
Note the difference between assignment through a
<tt><A href="FrontInsertionSequence.html">FrontInsertionSequence</A>::iterator</tt> and assignment through an
<tt>front_insert_iterator<<A href="FrontInsertionSequence.html">FrontInsertionSequence</A>></tt>. If <tt>i</tt> is a valid
<tt><A href="FrontInsertionSequence.html">FrontInsertionSequence</A>::iterator</tt>, then it points to some particular
element in the <A href="FrontInsertionSequence.html">front insertion sequence</A>; the expression <tt>*i = t</tt>
replaces that element with <tt>t</tt>, and does not change the total number
of elements in the sequence. If <tt>ii</tt> is a valid
<tt>front_insert_iterator<<A href="FrontInsertionSequence.html">FrontInsertionSequence</A>></tt>, however, then
the expression <tt>*ii = t</tt> is equivalent, for some <A href="FrontInsertionSequence.html">FrontInsertionSequence</A>
<tt>seq</tt>, to the expression <tt>seq.push_front(t)</tt>. That is, it does not overwrite
any of <tt>seq</tt>'s elements and it does change <tt>seq</tt>'s size.
<P><A name="2">[2]</A>
Note the difference between a <tt>front_insert_iterator</tt> and an
<tt><A href="insert_iterator.html">insert_iterator</A></tt>. It may seem that a <tt>front_insert_iterator</tt> is
the same as an <tt><A href="insert_iterator.html">insert_iterator</A></tt> constructed with an insertion
point that is the beginning of a sequence. In fact, though, there is
a very important difference: <b>every</b> assignment through a
<tt>front_insert_iterator</tt> corresponds to an insertion before the first
element of the sequence. If you are inserting elements at the
beginning of a sequence using an <tt>insert_iterator</tt>, then the elements
will appear in the order in which they were inserted. If, however,
you are inserting elements at the beginning of a sequence using a
<tt>front_insert_iterator</tt>, then the elements will appear in the reverse
of the order in which they were inserted.
<P><A name="3">[3]</A>
Note how assignment through an <tt>front_insert_iterator</tt> is implemented.
In general, unary <tt>operator*</tt> must be defined so that it returns a
proxy object, where the proxy object defines <tt>operator=</tt> to perform
the insert operation. In this case, for the sake of simplicity, the
proxy object is the <tt>front_insert_iterator</tt> itself. That is, <tt>*i</tt> simply
returns <tt>i</tt>, and <tt>*i = t</tt> is equivalent to <tt>i = t</tt>. You should not,
however, rely on this behavior. It is an implementation detail,
and it is not guaranteed to remain the same in future versions.
<P><A name="4">[4]</A>
This function exists solely for the sake of convenience:
since it is a non-member function, the template parameters may be
inferred and the type of the <tt>front_insert_iterator</tt> need not be declared
explicitly. One easy way to reverse a range and insert it
at the beginning of a <A href="FrontInsertionSequence.html">Front Insertion Sequence</A> <tt>S</tt>, for example, is
<tt><A href="copy.html">copy</A>(first, last, front_inserter(S))</tt>.
<h3>See also</h3>
<A href="insert_iterator.html">insert_iterator</A>, <A href="back_insert_iterator.html">back_insert_iterator</A>, <A href="OutputIterator.html">Output Iterator</A>,
<A href="Sequence.html">Sequence</A>, <A href="FrontInsertionSequence.html">Front Insertion Sequence</A>, <A href="Iterators.html">Iterator overview</A>
<!--start footer-->
<HR SIZE="6">
<A href="http://www.sgi.com/"><IMG SRC="surf.gif" HEIGHT="54" WIDTH="54"
ALT="[Silicon Surf]"></A>
<A HREF="index.html"><IMG SRC="stl_home.gif"
HEIGHT="54" WIDTH="54" ALT="[STL Home]"></A>
<BR>
<FONT SIZE="-2">
<A href="http://www.sgi.com/Misc/sgi_info.html" TARGET="_top">Copyright ©
1999 Silicon Graphics, Inc.</A> All Rights Reserved.</FONT>
<FONT SIZE="-3"><a href="http://www.sgi.com/Misc/external.list.html" TARGET="_top">TrademarkInformation</A>
</FONT>
<P>
</BODY>
</HTML>
|
