1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>is_valid (with message and strategy)</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="../is_valid.html" title="is_valid"> 9<link rel="prev" href="is_valid_2_with_failure_value.html" title="is_valid (with failure value)"> 10<link rel="next" href="is_valid_2_with_message.html" title="is_valid (with message)"> 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="is_valid_2_with_failure_value.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../is_valid.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="is_valid_2_with_message.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy"></a><a class="link" href="is_valid_3_with_message_and_strategy.html" title="is_valid (with message and strategy)">is_valid 28 (with message and strategy)</a> 29</h5></div></div></div> 30<p> 31 <a class="indexterm" name="idm45635693601632"></a> 32Checks if a geometry is valid (in the OGC sense) 33 </p> 34<h6> 35<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h0"></a> 36 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.synopsis"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.synopsis">Synopsis</a> 37 </h6> 38<p> 39</p> 40<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> <span class="keyword">typename</span> <span class="identifier">Strategy</span><span class="special">></span> 41<span class="keyword">bool</span> <span class="identifier">is_valid</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> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">&</span> <span class="identifier">message</span><span class="special">,</span> <span class="identifier">Strategy</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">strategy</span><span class="special">)</span></pre> 42<p> 43 </p> 44<h6> 45<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h1"></a> 46 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.parameters"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.parameters">Parameters</a> 47 </h6> 48<div class="informaltable"><table class="table"> 49<colgroup> 50<col> 51<col> 52<col> 53<col> 54</colgroup> 55<thead><tr> 56<th> 57 <p> 58 Type 59 </p> 60 </th> 61<th> 62 <p> 63 Concept 64 </p> 65 </th> 66<th> 67 <p> 68 Name 69 </p> 70 </th> 71<th> 72 <p> 73 Description 74 </p> 75 </th> 76</tr></thead> 77<tbody> 78<tr> 79<td> 80 <p> 81 Geometry const & 82 </p> 83 </td> 84<td> 85 <p> 86 Any type fulfilling a Geometry Concept 87 </p> 88 </td> 89<td> 90 <p> 91 geometry 92 </p> 93 </td> 94<td> 95 <p> 96 A model of the specified concept 97 </p> 98 </td> 99</tr> 100<tr> 101<td> 102 <p> 103 std::string & 104 </p> 105 </td> 106<td> 107 </td> 108<td> 109 <p> 110 message 111 </p> 112 </td> 113<td> 114 <p> 115 A string containing a message stating if the geometry is valid 116 or not, and if not valid a reason why 117 </p> 118 </td> 119</tr> 120<tr> 121<td> 122 <p> 123 Strategy const & 124 </p> 125 </td> 126<td> 127 <p> 128 Any type fulfilling a Is_valid Strategy Concept 129 </p> 130 </td> 131<td> 132 <p> 133 strategy 134 </p> 135 </td> 136<td> 137 <p> 138 The strategy which will be used for is_valid calculations 139 </p> 140 </td> 141</tr> 142</tbody> 143</table></div> 144<h6> 145<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h2"></a> 146 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.returns"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.returns">Returns</a> 147 </h6> 148<p> 149 Returns true if the geometry is valid (in the OGC sense); furthermore, 150 the following geometries are considered valid: multi-geometries with 151 no elements, linear geometries containing spikes, areal geometries with 152 duplicate (consecutive) points 153 </p> 154<h6> 155<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h3"></a> 156 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.header"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.header">Header</a> 157 </h6> 158<p> 159 Either 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">hpp</span><span class="special">></span></code> 163 </p> 164<p> 165 Or 166 </p> 167<p> 168 <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">is_valid</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 169 </p> 170<h6> 171<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h4"></a> 172 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.conformance"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.conformance">Conformance</a> 173 </h6> 174<p> 175 The function is_valid is not defined by OGC. 176 </p> 177<h6> 178<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h5"></a> 179 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.supported_geometries"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.supported_geometries">Supported 180 geometries</a> 181 </h6> 182<div class="informaltable"><table class="table"> 183<colgroup> 184<col> 185<col> 186</colgroup> 187<thead><tr> 188<th> 189 <p> 190 Geometry 191 </p> 192 </th> 193<th> 194 <p> 195 Status 196 </p> 197 </th> 198</tr></thead> 199<tbody> 200<tr> 201<td> 202 <p> 203 Point 204 </p> 205 </td> 206<td> 207 <p> 208 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 209 </p> 210 </td> 211</tr> 212<tr> 213<td> 214 <p> 215 Segment 216 </p> 217 </td> 218<td> 219 <p> 220 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 221 </p> 222 </td> 223</tr> 224<tr> 225<td> 226 <p> 227 Box 228 </p> 229 </td> 230<td> 231 <p> 232 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 233 </p> 234 </td> 235</tr> 236<tr> 237<td> 238 <p> 239 Linestring 240 </p> 241 </td> 242<td> 243 <p> 244 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 245 </p> 246 </td> 247</tr> 248<tr> 249<td> 250 <p> 251 Ring 252 </p> 253 </td> 254<td> 255 <p> 256 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 257 </p> 258 </td> 259</tr> 260<tr> 261<td> 262 <p> 263 Polygon 264 </p> 265 </td> 266<td> 267 <p> 268 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 269 </p> 270 </td> 271</tr> 272<tr> 273<td> 274 <p> 275 MultiPoint 276 </p> 277 </td> 278<td> 279 <p> 280 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 281 </p> 282 </td> 283</tr> 284<tr> 285<td> 286 <p> 287 MultiLinestring 288 </p> 289 </td> 290<td> 291 <p> 292 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 293 </p> 294 </td> 295</tr> 296<tr> 297<td> 298 <p> 299 MultiPolygon 300 </p> 301 </td> 302<td> 303 <p> 304 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 305 </p> 306 </td> 307</tr> 308<tr> 309<td> 310 <p> 311 Variant 312 </p> 313 </td> 314<td> 315 <p> 316 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 317 </p> 318 </td> 319</tr> 320</tbody> 321</table></div> 322<h6> 323<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h6"></a> 324 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.complexity"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.complexity">Complexity</a> 325 </h6> 326<p> 327 Constant-time for points, segments, boxes and multi-points 328 </p> 329<p> 330 Linear for linestrings and multi-linestrings 331 </p> 332<p> 333 Linearithmic for rings 334 </p> 335<p> 336 Currently, worst-case quadratic for polygons and multi-polygons 337 </p> 338<h6> 339<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h7"></a> 340 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.example"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.example">Example</a> 341 </h6> 342<p> 343 Checks whether a geometry is valid and, if not valid, prints a message 344 describing the reason 345 </p> 346<p> 347</p> 348<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 349<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> 350 351<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> 352<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> 353<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> 354 355 356<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 357<span class="special">{</span> 358 <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">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> <span class="identifier">point_type</span><span class="special">;</span> 359 <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">polygon</span><span class="special"><</span><span class="identifier">point_type</span><span class="special">></span> <span class="identifier">polygon_type</span><span class="special">;</span> 360 361 <span class="identifier">polygon_type</span> <span class="identifier">poly</span><span class="special">;</span> 362 <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">"POLYGON((0 0,0 10,10 10,10 0,0 0),(0 0,9 1,9 2,0 0),(0 0,2 9,1 9,0 0),(2 9,9 2,9 9,2 9))"</span><span class="special">,</span> <span class="identifier">poly</span><span class="special">);</span> 363 364 <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">message</span><span class="special">;</span> 365 <span class="keyword">bool</span> <span class="identifier">valid</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">is_valid</span><span class="special">(</span><span class="identifier">poly</span><span class="special">,</span> <span class="identifier">message</span><span class="special">);</span> 366 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"is valid? "</span> <span class="special"><<</span> <span class="special">(</span><span class="identifier">valid</span> <span class="special">?</span> <span class="string">"yes"</span> <span class="special">:</span> <span class="string">"no"</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> 367 <span class="keyword">if</span> <span class="special">(!</span> <span class="identifier">valid</span><span class="special">)</span> 368 <span class="special">{</span> 369 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"why not valid? "</span> <span class="special"><<</span> <span class="identifier">message</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> 370 <span class="special">}</span> 371 372 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 373<span class="special">}</span> 374</pre> 375<p> 376 </p> 377<p> 378 Output: 379 </p> 380<pre class="programlisting">is valid? no 381why not valid? Geometry has disconnected interior 382 383<img src="../../../../img/algorithms/is_valid_example.png" alt="is_valid_example"> 384 385</pre> 386<h6> 387<a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.h8"></a> 388 <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.see_also"></a></span><a class="link" href="is_valid_3_with_message_and_strategy.html#geometry.reference.algorithms.is_valid.is_valid_3_with_message_and_strategy.see_also">See 389 also</a> 390 </h6> 391<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> 392 <a class="link" href="../is_simple.html" title="is_simple">is_simple</a> 393 </li></ul></div> 394</div> 395<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 396<td align="left"></td> 397<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 398 Wulkiewicz, Oracle and/or its affiliates<p> 399 Distributed under the Boost Software License, Version 1.0. (See accompanying 400 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>) 401 </p> 402</div></td> 403</tr></table> 404<hr> 405<div class="spirit-nav"> 406<a accesskey="p" href="is_valid_2_with_failure_value.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../is_valid.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="is_valid_2_with_message.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 407</div> 408</body> 409</html> 410
