1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>segment_view</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. Geometry"> 8<link rel="up" href="../views.html" title="Views"> 9<link rel="prev" href="box_view.html" title="box_view"> 10<link rel="next" href="closeable_view.html" title="closeable_view"> 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="box_view.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../views.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="closeable_view.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="geometry.reference.views.segment_view"></a><a class="link" href="segment_view.html" title="segment_view">segment_view</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635666690624"></a> 31Makes a segment behave like a linestring or a range. 32 </p> 33<h6> 34<a name="geometry.reference.views.segment_view.h0"></a> 35 <span class="phrase"><a name="geometry.reference.views.segment_view.description"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.description">Description</a> 36 </h6> 37<p> 38 Adapts a segment to the Boost.Range concept, enabling the user to iterate 39 the two segment points. The segment_view is registered as a LineString 40 Concept 41 </p> 42<h6> 43<a name="geometry.reference.views.segment_view.h1"></a> 44 <span class="phrase"><a name="geometry.reference.views.segment_view.model_of"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.model_of">Model 45 of</a> 46 </h6> 47<p> 48 <a class="link" href="../concepts/concept_linestring.html" title="Linestring Concept">LineString 49 Concept</a> 50 </p> 51<h6> 52<a name="geometry.reference.views.segment_view.h2"></a> 53 <span class="phrase"><a name="geometry.reference.views.segment_view.synopsis"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.synopsis">Synopsis</a> 54 </h6> 55<p> 56</p> 57<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Segment</span><span class="special">></span> 58<span class="keyword">struct</span> <span class="identifier">segment_view</span> 59 <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">detail</span><span class="special">::</span><span class="identifier">points_view</span><span class="special"><</span> <span class="identifier">geometry</span><span class="special">::</span><span class="identifier">point_type</span><span class="special"><</span> <span class="identifier">Segment</span> <span class="special">>::</span><span class="identifier">type</span><span class="special">,</span> <span class="number">2</span> <span class="special">></span> 60<span class="special">{</span> 61 <span class="comment">// ...</span> 62<span class="special">};</span> 63</pre> 64<p> 65 </p> 66<h6> 67<a name="geometry.reference.views.segment_view.h3"></a> 68 <span class="phrase"><a name="geometry.reference.views.segment_view.template_parameter_s_"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.template_parameter_s_">Template 69 parameter(s)</a> 70 </h6> 71<div class="informaltable"><table class="table"> 72<colgroup> 73<col> 74<col> 75</colgroup> 76<thead><tr> 77<th> 78 <p> 79 Parameter 80 </p> 81 </th> 82<th> 83 <p> 84 Description 85 </p> 86 </th> 87</tr></thead> 88<tbody><tr> 89<td> 90 <p> 91 typename Segment 92 </p> 93 </td> 94<td> 95 <p> 96 A type fulfilling the Segment Concept 97 </p> 98 </td> 99</tr></tbody> 100</table></div> 101<h6> 102<a name="geometry.reference.views.segment_view.h4"></a> 103 <span class="phrase"><a name="geometry.reference.views.segment_view.constructor_s_"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.constructor_s_">Constructor(s)</a> 104 </h6> 105<div class="informaltable"><table class="table"> 106<colgroup> 107<col> 108<col> 109<col> 110</colgroup> 111<thead><tr> 112<th> 113 <p> 114 Function 115 </p> 116 </th> 117<th> 118 <p> 119 Description 120 </p> 121 </th> 122<th> 123 <p> 124 Parameters 125 </p> 126 </th> 127</tr></thead> 128<tbody><tr> 129<td> 130 <p> 131</p> 132<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">segment_view</span><span class="special">(</span><span class="identifier">Segment</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">segment</span><span class="special">)</span></pre> 133<p> 134 </p> 135 </td> 136<td> 137 <p> 138 Constructor accepting the segment to adapt. 139 </p> 140 </td> 141<td> 142 <p> 143 <span class="bold"><strong>Segment const &</strong></span>: <span class="emphasis"><em>segment</em></span>: 144 </p> 145 </td> 146</tr></tbody> 147</table></div> 148<h6> 149<a name="geometry.reference.views.segment_view.h5"></a> 150 <span class="phrase"><a name="geometry.reference.views.segment_view.header"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.header">Header</a> 151 </h6> 152<p> 153 Either 154 </p> 155<p> 156 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 157 </p> 158<p> 159 Or 160 </p> 161<p> 162 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">views</span><span class="special">/</span><span class="identifier">segment_view</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 163 </p> 164<h6> 165<a name="geometry.reference.views.segment_view.h6"></a> 166 <span class="phrase"><a name="geometry.reference.views.segment_view.complexity"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.complexity">Complexity</a> 167 </h6> 168<p> 169 Compile time 170 </p> 171<h6> 172<a name="geometry.reference.views.segment_view.h7"></a> 173 <span class="phrase"><a name="geometry.reference.views.segment_view.example"></a></span><a class="link" href="segment_view.html#geometry.reference.views.segment_view.example">Example</a> 174 </h6> 175<p> 176 Shows usage of the Boost.Range compatible view on a box 177 </p> 178<p> 179</p> 180<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 181 182<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 183 184 185<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 186<span class="special">{</span> 187 <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">segment</span> 188 <span class="special"><</span> 189 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">point</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="number">2</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">cs</span><span class="special">::</span><span class="identifier">cartesian</span><span class="special">></span> 190 <span class="special">></span> <span class="identifier">segment_type</span><span class="special">;</span> 191 192 <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">segment_view</span><span class="special"><</span><span class="identifier">segment_type</span><span class="special">></span> <span class="identifier">segment_view</span><span class="special">;</span> 193 194 <span class="identifier">segment_type</span> <span class="identifier">segment</span><span class="special">;</span> 195 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">assign_values</span><span class="special">(</span><span class="identifier">segment</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span> <span class="number">1</span><span class="special">);</span> 196 197 <span class="identifier">segment_view</span> <span class="identifier">view</span><span class="special">(</span><span class="identifier">segment</span><span class="special">);</span> 198 199 <span class="comment">// Iterating over the points of this segment</span> 200 <span class="keyword">for</span> <span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_iterator</span><span class="special"><</span><span class="identifier">segment_view</span> <span class="keyword">const</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">view</span><span class="special">);</span> 201 <span class="identifier">it</span> <span class="special">!=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">end</span><span class="special">(</span><span class="identifier">view</span><span class="special">);</span> <span class="special">++</span><span class="identifier">it</span><span class="special">)</span> 202 <span class="special">{</span> 203 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">" "</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">dsv</span><span class="special">(*</span><span class="identifier">it</span><span class="special">);</span> 204 <span class="special">}</span> 205 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> 206 207 <span class="comment">// Note that a segment_view is tagged as a linestring, so supports length etc.</span> 208 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Length: "</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">length</span><span class="special">(</span><span class="identifier">view</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> 209 210 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 211<span class="special">}</span> 212</pre> 213<p> 214 </p> 215<p> 216 Output: 217 </p> 218<pre class="programlisting">(0, 0) (1, 1) 219Length: 1.41421 220</pre> 221</div> 222<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 223<td align="left"></td> 224<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 225 Wulkiewicz, Oracle and/or its affiliates<p> 226 Distributed under the Boost Software License, Version 1.0. (See accompanying 227 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>) 228 </p> 229</div></td> 230</tr></table> 231<hr> 232<div class="spirit-nav"> 233<a accesskey="p" href="box_view.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../views.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="closeable_view.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 234</div> 235</body> 236</html> 237
