1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>deque</title> 5<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../index.html" title="Chapter 1. Fusion 2.2"> 8<link rel="up" href="../container.html" title="Container"> 9<link rel="prev" href="list.html" title="list"> 10<link rel="next" href="front_extended_deque.html" title="front_extended_deque"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="list.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../container.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="front_extended_deque.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="fusion.container.deque"></a><a class="link" href="deque.html" title="deque">deque</a> 28</h3></div></div></div> 29<h5> 30<a name="fusion.container.deque.h0"></a> 31 <span class="phrase"><a name="fusion.container.deque.description"></a></span><a class="link" href="deque.html#fusion.container.deque.description">Description</a> 32 </h5> 33<p> 34 <code class="computeroutput"><span class="identifier">deque</span></code> is a simple <a class="link" href="../sequence/concepts/bidirectional_sequence.html" title="Bidirectional Sequence">Bidirectional 35 Sequence</a> that supports constant-time insertion and removal of elements 36 at both ends. Like the <a class="link" href="list.html" title="list"><code class="computeroutput"><span class="identifier">list</span></code></a> and <a class="link" href="cons.html" title="cons"><code class="computeroutput"><span class="identifier">cons</span></code></a>, <code class="computeroutput"><span class="identifier">deque</span></code> 37 is more efficient than <a class="link" href="vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a> (especially at compile time) 38 when the target sequence is constructed piecemeal (a data at a time, e.g. 39 when constructing expression templates). Like the <a class="link" href="list.html" title="list"><code class="computeroutput"><span class="identifier">list</span></code></a> and <a class="link" href="cons.html" title="cons"><code class="computeroutput"><span class="identifier">cons</span></code></a>, runtime cost of access to 40 each element is peculiarly constant (see <a class="link" href="../notes.html#fusion.notes.recursive_inlined_functions">Recursive 41 Inlined Functions</a>). 42 </p> 43<p> 44 Element insertion and removal are done by special <code class="computeroutput"><span class="identifier">deque</span></code> 45 helper classes <a class="link" href="front_extended_deque.html" title="front_extended_deque"><code class="computeroutput"><span class="identifier">front_extended_deque</span></code></a> and <a class="link" href="back_extended_deque.html" title="back_extended_deque"><code class="computeroutput"><span class="identifier">back_extended_deque</span></code></a>. 46 </p> 47<h5> 48<a name="fusion.container.deque.h1"></a> 49 <span class="phrase"><a name="fusion.container.deque.header"></a></span><a class="link" href="deque.html#fusion.container.deque.header">Header</a> 50 </h5> 51<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">container</span><span class="special">/</span><span class="identifier">deque</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 52<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">deque</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 53<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">container</span><span class="special">/</span><span class="identifier">deque</span><span class="special">/</span><span class="identifier">deque_fwd</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 54<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">deque_fwd</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 55</pre> 56<h5> 57<a name="fusion.container.deque.h2"></a> 58 <span class="phrase"><a name="fusion.container.deque.synopsis"></a></span><a class="link" href="deque.html#fusion.container.deque.synopsis">Synopsis</a> 59 </h5> 60<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="special">...</span><span class="identifier">Elements</span><span class="special">></span> 61<span class="keyword">struct</span> <span class="identifier">deque</span><span class="special">;</span> 62</pre> 63<p> 64 For C++11 compilers, the variadic class interface has no upper bound. 65 </p> 66<p> 67 For C++03 compilers, the variadic class interface accepts <code class="computeroutput"><span class="number">0</span></code> 68 to <code class="computeroutput"><span class="identifier">FUSION_MAX_DEQUE_SIZE</span></code> 69 elements, where <code class="computeroutput"><span class="identifier">FUSION_MAX_DEQUE_SIZE</span></code> 70 is a user definable predefined maximum that defaults to <code class="computeroutput"><span class="number">10</span></code>. 71 Example: 72 </p> 73<pre class="programlisting"><span class="identifier">deque</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">char</span><span class="special">,</span> <span class="keyword">double</span><span class="special">></span> 74</pre> 75<p> 76 You may define the preprocessor constant <code class="computeroutput"><span class="identifier">FUSION_MAX_DEQUE_SIZE</span></code> 77 before including any Fusion header to change the default. Example: 78 </p> 79<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">FUSION_MAX_DEQUE_SIZE</span> <span class="number">20</span> 80</pre> 81<h5> 82<a name="fusion.container.deque.h3"></a> 83 <span class="phrase"><a name="fusion.container.deque.template_parameters"></a></span><a class="link" href="deque.html#fusion.container.deque.template_parameters">Template 84 parameters</a> 85 </h5> 86<div class="informaltable"><table class="table"> 87<colgroup> 88<col> 89<col> 90<col> 91</colgroup> 92<thead><tr> 93<th> 94 <p> 95 Parameter 96 </p> 97 </th> 98<th> 99 <p> 100 Description 101 </p> 102 </th> 103<th> 104 <p> 105 Default 106 </p> 107 </th> 108</tr></thead> 109<tbody><tr> 110<td> 111 <p> 112 <code class="computeroutput"><span class="identifier">Elements</span></code> 113 </p> 114 </td> 115<td> 116 <p> 117 Element types 118 </p> 119 </td> 120<td> 121 </td> 122</tr></tbody> 123</table></div> 124<h5> 125<a name="fusion.container.deque.h4"></a> 126 <span class="phrase"><a name="fusion.container.deque.model_of"></a></span><a class="link" href="deque.html#fusion.container.deque.model_of">Model 127 of</a> 128 </h5> 129<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> 130 <a class="link" href="../sequence/concepts/bidirectional_sequence.html" title="Bidirectional Sequence">Bidirectional 131 Sequence</a> 132 </li></ul></div> 133<div class="variablelist"> 134<p class="title"><b>Notation</b></p> 135<dl class="variablelist"> 136<dt><span class="term"><code class="computeroutput"><span class="identifier">D</span></code></span></dt> 137<dd><p> 138 A <code class="computeroutput"><span class="identifier">deque</span></code> type 139 </p></dd> 140<dt><span class="term"><code class="computeroutput"><span class="identifier">d</span></code>, <code class="computeroutput"><span class="identifier">d2</span></code></span></dt> 141<dd><p> 142 Instances of <code class="computeroutput"><span class="identifier">deque</span></code> 143 </p></dd> 144<dt><span class="term"><code class="computeroutput"><span class="identifier">e0</span></code>...<code class="computeroutput"><span class="identifier">en</span></code></span></dt> 145<dd><p> 146 Heterogeneous values 147 </p></dd> 148<dt><span class="term"><code class="computeroutput"><span class="identifier">s</span></code></span></dt> 149<dd><p> 150 A <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward 151 Sequence</a> 152 </p></dd> 153<dt><span class="term"><code class="computeroutput"><span class="identifier">N</span></code></span></dt> 154<dd><p> 155 An <a href="http://www.boost.org/libs/mpl/doc/refmanual/integral-constant.html" target="_top">MPL 156 Integral Constant</a> 157 </p></dd> 158</dl> 159</div> 160<h5> 161<a name="fusion.container.deque.h5"></a> 162 <span class="phrase"><a name="fusion.container.deque.expression_semantics"></a></span><a class="link" href="deque.html#fusion.container.deque.expression_semantics">Expression 163 Semantics</a> 164 </h5> 165<p> 166 Semantics of an expression is defined only where it differs from, or is not 167 defined in <a class="link" href="../sequence/concepts/bidirectional_sequence.html" title="Bidirectional Sequence">Bidirectional 168 Sequence</a>. 169 </p> 170<div class="informaltable"><table class="table"> 171<colgroup> 172<col> 173<col> 174</colgroup> 175<thead><tr> 176<th> 177 <p> 178 Expression 179 </p> 180 </th> 181<th> 182 <p> 183 Semantics 184 </p> 185 </th> 186</tr></thead> 187<tbody> 188<tr> 189<td> 190 <p> 191 <code class="computeroutput"><span class="identifier">D</span><span class="special">()</span></code> 192 </p> 193 </td> 194<td> 195 <p> 196 Creates a deque with default constructed elements. 197 </p> 198 </td> 199</tr> 200<tr> 201<td> 202 <p> 203 <code class="computeroutput"><span class="identifier">D</span><span class="special">(</span><span class="identifier">e0</span><span class="special">,</span> 204 <span class="identifier">e1</span><span class="special">,...</span> 205 <span class="identifier">en</span><span class="special">)</span></code> 206 </p> 207 </td> 208<td> 209 <p> 210 Creates a deque with elements <code class="computeroutput"><span class="identifier">e0</span></code>...<code class="computeroutput"><span class="identifier">en</span></code>. 211 </p> 212 </td> 213</tr> 214<tr> 215<td> 216 <p> 217 <code class="computeroutput"><span class="identifier">D</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> 218 </p> 219 </td> 220<td> 221 <p> 222 Copy constructs a deque from a <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward 223 Sequence</a>, <code class="computeroutput"><span class="identifier">s</span></code>. 224 </p> 225 </td> 226</tr> 227<tr> 228<td> 229 <p> 230 <code class="computeroutput"><span class="identifier">d</span> <span class="special">=</span> 231 <span class="identifier">s</span></code> 232 </p> 233 </td> 234<td> 235 <p> 236 Assigns to a deque, <code class="computeroutput"><span class="identifier">d</span></code>, 237 from a <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward 238 Sequence</a>, <code class="computeroutput"><span class="identifier">s</span></code>. 239 </p> 240 </td> 241</tr> 242<tr> 243<td> 244 <p> 245 <code class="computeroutput"><a class="link" href="../sequence/intrinsic/functions/at.html" title="at"><code class="computeroutput"><span class="identifier">at</span></code></a><span class="special"><</span><span class="identifier">N</span><span class="special">>(</span><span class="identifier">d</span><span class="special">)</span></code> 246 </p> 247 </td> 248<td> 249 <p> 250 The Nth element from the beginning of the sequence; see <a class="link" href="../sequence/intrinsic/functions/at.html" title="at"><code class="computeroutput"><span class="identifier">at</span></code></a>. 251 </p> 252 </td> 253</tr> 254</tbody> 255</table></div> 256<div class="note"><table border="0" summary="Note"> 257<tr> 258<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td> 259<th align="left">Note</th> 260</tr> 261<tr><td align="left" valign="top"><p> 262 <code class="computeroutput"><a class="link" href="../sequence/intrinsic/functions/at.html" title="at"><code class="computeroutput"><span class="identifier">at</span></code></a><span class="special"><</span><span class="identifier">N</span><span class="special">>(</span><span class="identifier">d</span><span class="special">)</span></code> is 263 provided for convenience, despite <code class="computeroutput"><span class="identifier">deque</span></code> 264 being a <a class="link" href="../sequence/concepts/bidirectional_sequence.html" title="Bidirectional Sequence">Bidirectional 265 Sequence</a> only (<code class="computeroutput"><span class="identifier">at</span></code> 266 is supposed to be a <a class="link" href="../sequence/concepts/random_access_sequence.html" title="Random Access Sequence">Random 267 Access Sequence</a> requirement). The runtime complexity of <a class="link" href="../sequence/intrinsic/functions/at.html" title="at"><code class="computeroutput"><span class="identifier">at</span></code></a> is constant (see <a class="link" href="../notes.html#fusion.notes.recursive_inlined_functions">Recursive 268 Inlined Functions</a>). <code class="computeroutput"><span class="identifier">deque</span></code> 269 element access utilizes operator overloading with argument dependent lookup 270 (ADL) of the proper element getter function given a static constant index 271 parameter. Interestingly, with modern C++ compilers, this lookup is very 272 fast and rivals recursive template instantiations in compile time-speed, 273 so much so that <code class="computeroutput"><span class="identifier">deque</span></code> relies 274 on ADL for all element access (indexing) as well as iteration. 275 </p></td></tr> 276</table></div> 277<h5> 278<a name="fusion.container.deque.h6"></a> 279 <span class="phrase"><a name="fusion.container.deque.example"></a></span><a class="link" href="deque.html#fusion.container.deque.example">Example</a> 280 </h5> 281<pre class="programlisting"><span class="identifier">deque</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">float</span><span class="special">></span> <span class="identifier">d</span><span class="special">(</span><span class="number">12</span><span class="special">,</span> <span class="number">5.5f</span><span class="special">);</span> 282<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <a class="link" href="../sequence/intrinsic/functions/at_c.html" title="at_c"><code class="computeroutput"><span class="identifier">at_c</span></code></a><span class="special"><</span><span class="number">0</span><span class="special">>(</span><span class="identifier">d</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> 283<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <a class="link" href="../sequence/intrinsic/functions/at_c.html" title="at_c"><code class="computeroutput"><span class="identifier">at_c</span></code></a><span class="special"><</span><span class="number">1</span><span class="special">>(</span><span class="identifier">d</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> 284</pre> 285</div> 286<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 287<td align="left"></td> 288<td align="right"><div class="copyright-footer">Copyright © 2001-2006, 2011, 2012 Joel de Guzman, 289 Dan Marsden, Tobias Schwinger<p> 290 Distributed under the Boost Software License, Version 1.0. (See accompanying 291 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 292 </p> 293</div></td> 294</tr></table> 295<hr> 296<div class="spirit-nav"> 297<a accesskey="p" href="list.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../container.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="front_extended_deque.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 298</div> 299</body> 300</html> 301
