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<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value"></a><a class="link" href="is_valid_2_with_failure_value.html" title="is_valid (with failure value)">is_valid
(with failure value)</a>
</h5></div></div></div>
<p>
<a class="indexterm" name="idp115154352"></a>
Checks if a geometry is valid (in the OGC sense)
</p>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h0"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.synopsis"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.synopsis">Synopsis</a>
</h6>
<p>
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">&gt;</span>
<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">&amp;</span> <span class="identifier">geometry</span><span class="special">,</span> <span class="identifier">validity_failure_type</span> <span class="special">&amp;</span> <span class="identifier">failure</span><span class="special">)</span></pre>
<p>
</p>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h1"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.parameters"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.parameters">Parameters</a>
</h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Type
</p>
</th>
<th>
<p>
Concept
</p>
</th>
<th>
<p>
Name
</p>
</th>
<th>
<p>
Description
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
Geometry const &amp;
</p>
</td>
<td>
<p>
Any type fulfilling a Geometry Concept
</p>
</td>
<td>
<p>
geometry
</p>
</td>
<td>
<p>
A model of the specified concept
</p>
</td>
</tr>
<tr>
<td>
<p>
validity_failure_type &amp;
</p>
</td>
<td>
</td>
<td>
<p>
failure
</p>
</td>
<td>
<p>
An enumeration value indicating that the geometry is valid
or not, and if not valid indicating the reason why
</p>
</td>
</tr>
</tbody>
</table></div>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h2"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.returns"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.returns">Returns</a>
</h6>
<p>
Returns true if the geometry is valid (in the OGC sense); furthermore,
the following geometries are considered valid: multi-geometries with
no elements, linear geometries containing spikes, areal geometries with
duplicate (consecutive) points
</p>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h3"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.header"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.header">Header</a>
</h6>
<p>
Either
</p>
<p>
<code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span></code>
</p>
<p>
Or
</p>
<p>
<code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span></code>
</p>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h4"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.conformance"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.conformance">Conformance</a>
</h6>
<p>
The function is_valid is not defined by OGC.
</p>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h5"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.supported_geometries"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.supported_geometries">Supported
geometries</a>
</h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Geometry
</p>
</th>
<th>
<p>
Status
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
Point
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
Segment
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
Box
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
Linestring
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
Ring
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
Polygon
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
MultiPoint
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
MultiLinestring
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
MultiPolygon
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
<tr>
<td>
<p>
Variant
</p>
</td>
<td>
<p>
<span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
</p>
</td>
</tr>
</tbody>
</table></div>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h6"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.complexity"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.complexity">Complexity</a>
</h6>
<p>
Constant-time for points, segments, boxes and multi-points
</p>
<p>
Linear for linestrings and multi-linestrings
</p>
<p>
Linearithmic for rings
</p>
<p>
Currently, worst-case quadratic for polygons and multi-polygons
</p>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h7"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.example"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.example">Example</a>
</h6>
<p>
Checks whether a geometry is valid and, if not valid, checks if it could
be fixed by bg::correct; if so bg::correct is called on the geometry
</p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span>
<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
<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">&lt;</span><span class="keyword">double</span><span class="special">&gt;</span> <span class="identifier">point_type</span><span class="special">;</span>
<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">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">polygon_type</span><span class="special">;</span>
<span class="identifier">polygon_type</span> <span class="identifier">poly</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">read_wkt</span><span class="special">(</span><span class="string">"POLYGON((0 0,0 10,10 10,10 0),(0 0,9 2,9 1,0 0),(0 0,2 9,1 9,0 0))"</span><span class="special">,</span> <span class="identifier">poly</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"original geometry: "</span> <span class="special">&lt;&lt;</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">poly</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</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">validity_failure_type</span> <span class="identifier">failure</span><span class="special">;</span>
<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">failure</span><span class="special">);</span>
<span class="comment">// if the invalidity is only due to lack of closing points and/or wrongly oriented rings, then bg::correct can fix it</span>
<span class="keyword">bool</span> <span class="identifier">could_be_fixed</span> <span class="special">=</span> <span class="special">(</span><span class="identifier">failure</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">failure_not_closed</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">failure_wrong_orientation</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"is valid? "</span> <span class="special">&lt;&lt;</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">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="keyword">if</span> <span class="special">(!</span> <span class="identifier">valid</span><span class="special">)</span>
<span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"can boost::geometry::correct remedy invalidity? "</span> <span class="special">&lt;&lt;</span> <span class="special">(</span><span class="identifier">could_be_fixed</span> <span class="special">?</span> <span class="string">"possibly yes"</span> <span class="special">:</span> <span class="string">"no"</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">could_be_fixed</span><span class="special">)</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">correct</span><span class="special">(</span><span class="identifier">poly</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"after correction: "</span> <span class="special">&lt;&lt;</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="special">?</span> <span class="string">"valid"</span> <span class="special">:</span> <span class="string">"still invalid"</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"corrected geometry: "</span> <span class="special">&lt;&lt;</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">poly</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
<span class="special">}</span>
<span class="special">}</span>
<span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
</p>
<p>
Output:
</p>
<pre class="programlisting">original geometry: (((0, 0), (0, 10), (10, 10), (10, 0)), ((0, 0), (9, 2), (9, 1), (0, 0)), ((0, 0), (2, 9), (1, 9), (0, 0)))
is valid? no
can boost::geometry::correct remedy invalidity? possibly yes
after correction: valid
corrected geometry: (((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)))
<img src="../../../../img/algorithms/is_valid_failure_example.png" alt="is_valid_failure_example">
</pre>
<h6>
<a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.h8"></a>
<span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.see_also"></a></span><a class="link" href="is_valid_2_with_failure_value.html#geometry.reference.algorithms.is_valid.is_valid_2_with_failure_value.see_also">See
also</a>
</h6>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<a class="link" href="../is_simple.html" title="is_simple">is_simple</a>
</li>
<li class="listitem">
<a class="link" href="../../enumerations/validity_failure_type.html" title="validity_failure_type">validity_failure_type</a>
</li>
</ul></div>
</div>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2009-2015 Barend Gehrels, Bruno Lalande,
Mateusz Loskot, Adam Wulkiewicz, Oracle and/or its affiliates<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
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