1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>num_interior_rings</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="../algorithms.html" title="Algorithms"> 9<link rel="prev" href="num_geometries.html" title="num_geometries"> 10<link rel="next" href="num_points.html" title="num_points"> 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="num_geometries.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../algorithms.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="num_points.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.algorithms.num_interior_rings"></a><a class="link" href="num_interior_rings.html" title="num_interior_rings">num_interior_rings</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635691693248"></a> 31Calculates the number of interior rings of a geometry. 32 </p> 33<h6> 34<a name="geometry.reference.algorithms.num_interior_rings.h0"></a> 35 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.description"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.description">Description</a> 36 </h6> 37<p> 38 The free function num_interior_rings calculates the number of interior 39 rings of a geometry. 40 </p> 41<h6> 42<a name="geometry.reference.algorithms.num_interior_rings.h1"></a> 43 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.synopsis"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.synopsis">Synopsis</a> 44 </h6> 45<p> 46</p> 47<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">></span> 48<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">num_interior_rings</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">geometry</span><span class="special">)</span></pre> 49<p> 50 </p> 51<h6> 52<a name="geometry.reference.algorithms.num_interior_rings.h2"></a> 53 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.parameters"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.parameters">Parameters</a> 54 </h6> 55<div class="informaltable"><table class="table"> 56<colgroup> 57<col> 58<col> 59<col> 60<col> 61</colgroup> 62<thead><tr> 63<th> 64 <p> 65 Type 66 </p> 67 </th> 68<th> 69 <p> 70 Concept 71 </p> 72 </th> 73<th> 74 <p> 75 Name 76 </p> 77 </th> 78<th> 79 <p> 80 Description 81 </p> 82 </th> 83</tr></thead> 84<tbody><tr> 85<td> 86 <p> 87 Geometry const & 88 </p> 89 </td> 90<td> 91 <p> 92 Any type fulfilling a Geometry Concept 93 </p> 94 </td> 95<td> 96 <p> 97 geometry 98 </p> 99 </td> 100<td> 101 <p> 102 A model of the specified concept 103 </p> 104 </td> 105</tr></tbody> 106</table></div> 107<h6> 108<a name="geometry.reference.algorithms.num_interior_rings.h3"></a> 109 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.returns"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.returns">Returns</a> 110 </h6> 111<p> 112 The calculated number of interior rings 113 </p> 114<h6> 115<a name="geometry.reference.algorithms.num_interior_rings.h4"></a> 116 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.header"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.header">Header</a> 117 </h6> 118<p> 119 Either 120 </p> 121<p> 122 <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> 123 </p> 124<p> 125 Or 126 </p> 127<p> 128 <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">algorithms</span><span class="special">/</span><span class="identifier">num_interior_rings</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 129 </p> 130<h6> 131<a name="geometry.reference.algorithms.num_interior_rings.h5"></a> 132 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.conformance"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.conformance">Conformance</a> 133 </h6> 134<p> 135 The function num_interior_ring implements function NumInteriorRing from 136 the <a href="http://www.opengeospatial.org/standards/sfa" target="_top">OGC Simple 137 Feature Specification</a>. 138 </p> 139<div class="note"><table border="0" summary="Note"> 140<tr> 141<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td> 142<th align="left">Note</th> 143</tr> 144<tr><td align="left" valign="top"><p> 145 Boost.Geometry adds an "s" 146 </p></td></tr> 147</table></div> 148<h6> 149<a name="geometry.reference.algorithms.num_interior_rings.h6"></a> 150 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.behavior"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.behavior">Behavior</a> 151 </h6> 152<div class="informaltable"><table class="table"> 153<colgroup> 154<col> 155<col> 156</colgroup> 157<thead><tr> 158<th> 159 <p> 160 Case 161 </p> 162 </th> 163<th> 164 <p> 165 Behavior 166 </p> 167 </th> 168</tr></thead> 169<tbody> 170<tr> 171<td> 172 <p> 173 Polygon 174 </p> 175 </td> 176<td> 177 <p> 178 Returns the number of its interior rings 179 </p> 180 </td> 181</tr> 182<tr> 183<td> 184 <p> 185 Multi Polygon 186 </p> 187 </td> 188<td> 189 <p> 190 Returns the number of the interior rings of all polygons 191 </p> 192 </td> 193</tr> 194<tr> 195<td> 196 <p> 197 Other geometries 198 </p> 199 </td> 200<td> 201 <p> 202 Returns 0 203 </p> 204 </td> 205</tr> 206</tbody> 207</table></div> 208<h6> 209<a name="geometry.reference.algorithms.num_interior_rings.h7"></a> 210 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.complexity"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.complexity">Complexity</a> 211 </h6> 212<p> 213 Constant 214 </p> 215<h6> 216<a name="geometry.reference.algorithms.num_interior_rings.h8"></a> 217 <span class="phrase"><a name="geometry.reference.algorithms.num_interior_rings.examples"></a></span><a class="link" href="num_interior_rings.html#geometry.reference.algorithms.num_interior_rings.examples">Examples</a> 218 </h6> 219<p> 220 Get the number of interior rings in a multi-polygon 221 </p> 222<p> 223</p> 224<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 225 226<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> 227<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">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 228<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">geometries</span><span class="special">/</span><span class="identifier">polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 229<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">geometries</span><span class="special">/</span><span class="identifier">multi_polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 230 231 232<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 233<span class="special">{</span> 234 <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">multi_polygon</span> 235 <span class="special"><</span> 236 <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">polygon</span> 237 <span class="special"><</span> 238 <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">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> 239 <span class="special">></span> 240 <span class="special">></span> <span class="identifier">mp</span><span class="special">;</span> 241 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">read_wkt</span><span class="special">(</span><span class="string">"MULTIPOLYGON(((0 0,0 10,10 0,0 0),(1 1,1 9,9 1,1 1)),((10 10,10 7,7 10,10 10)))"</span><span class="special">,</span> <span class="identifier">mp</span><span class="special">);</span> 242 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Number of interior rings: "</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">num_interior_rings</span><span class="special">(</span><span class="identifier">mp</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> 243 244 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 245<span class="special">}</span> 246</pre> 247<p> 248 </p> 249<p> 250 Output: 251 </p> 252<pre class="programlisting">Number of interior rings: 1 253</pre> 254</div> 255<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 256<td align="left"></td> 257<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 258 Wulkiewicz, Oracle and/or its affiliates<p> 259 Distributed under the Boost Software License, Version 1.0. (See accompanying 260 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>) 261 </p> 262</div></td> 263</tr></table> 264<hr> 265<div class="spirit-nav"> 266<a accesskey="p" href="num_geometries.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../algorithms.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="num_points.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 267</div> 268</body> 269</html> 270
