libs/geometry/doc/html/geometry/reference/spatial_indexes/boost__geometry__index__rtree/qbegin_predicates_const___.html

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  26 <div class="titlepage"><div><div><h5 class="title">
  27 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___"></a><a name="classboost_1_1geometry_1_1index_1_1rtree_1a63d15f3b5b157a47045fcac3fec3b7a0"></a><a class="link" href="qbegin_predicates_const___.html" title="qbegin(Predicates const &amp;)">qbegin(Predicates
  28           const &amp;)</a>
  29 </h5></div></div></div>
  30 <p>
  31             <a class="indexterm" name="idp116250752"></a>
  32 Returns a query iterator pointing at the begin of the query range.
  33           </p>
  34 <h6>
  35 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h0"></a>
  36             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.description"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.description">Description</a>
  37           </h6>
  38 <p>
  39             This method returns an iterator which may be used to perform iterative
  40             queries. For the information about predicates which may be passed to
  41             this method see <a class="link" href="query_predicates_const____outiter_.html#classboost_1_1geometry_1_1index_1_1rtree_1a7baa88eb4e7a5c640ab847513de45b3e">query()</a>.
  42           </p>
  43 <h6>
  44 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h1"></a>
  45             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.synopsis"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.synopsis">Synopsis</a>
  46           </h6>
  47 <pre class="programlisting"><code class="computeroutput"><span class="keyword">template</span><span class="special">&lt;</span></code><code class="computeroutput"><span class="keyword">typename</span> <span class="identifier">Predicates</span></code><code class="computeroutput"><span class="special">&gt;</span></code>
  48 <code class="literal"><a class="link" href="../boost__geometry__index__rtree.html#classboost_1_1geometry_1_1index_1_1rtree_1ad144a7704ad878caaa84cda79b140855">const_query_iterator</a></code> <code class="computeroutput"><span class="identifier">qbegin</span></code><code class="computeroutput"><span class="special">(</span></code><code class="computeroutput"><span class="identifier">Predicates</span> <span class="keyword">const</span> <span class="special">&amp;</span></code> <code class="computeroutput"><span class="identifier">predicates</span></code><code class="computeroutput"><span class="special">)</span></code>
  49 </pre>
  50 <h6>
  51 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h2"></a>
  52             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.modifier_s_"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.modifier_s_">Modifier(s)</a>
  53           </h6>
  54 <p>
  55 </p>
  56 <pre class="programlisting"><span class="keyword">const</span></pre>
  57 <p>
  58           </p>
  59 <h6>
  60 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h3"></a>
  61             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.parameter_s_"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.parameter_s_">Parameter(s)</a>
  62           </h6>
  63 <div class="informaltable"><table class="table">
  64 <colgroup>
  65 <col>
  66 <col>
  67 <col>
  68 </colgroup>
  69 <thead><tr>
  70 <th>
  71                     <p>
  72                       Type
  73                     </p>
  74                   </th>
  75 <th>
  76                     <p>
  77                       Name
  78                     </p>
  79                   </th>
  80 <th>
  81                     <p>
  82                       Description
  83                     </p>
  84                   </th>
  85 </tr></thead>
  86 <tbody><tr>
  87 <td>
  88                     <p>
  89                       <code class="computeroutput"><span class="identifier">Predicates</span> <span class="keyword">const</span> <span class="special">&amp;</span></code>
  90                     </p>
  91                   </td>
  92 <td>
  93                     <p>
  94                       <code class="computeroutput"><span class="identifier">predicates</span></code>
  95                     </p>
  96                   </td>
  97 <td>
  98                     <p>
  99                       Predicates.
 100                     </p>
 101                   </td>
 102 </tr></tbody>
 103 </table></div>
 104 <h6>
 105 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h4"></a>
 106             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.returns"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.returns">Returns</a>
 107           </h6>
 108 <p>
 109             The iterator pointing at the begin of the query range.
 110           </p>
 111 <h6>
 112 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h5"></a>
 113             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.example"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.example">Example</a>
 114           </h6>
 115 <p>
 116 </p>
 117 <pre class="programlisting"><span class="keyword">for</span> <span class="special">(</span> <span class="identifier">Rtree</span><span class="special">::</span><span class="identifier">const_query_iterator</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">tree</span><span class="special">.</span><span class="identifier">qbegin</span><span class="special">(</span><span class="identifier">bgi</span><span class="special">::</span><span class="identifier">nearest</span><span class="special">(</span><span class="identifier">pt</span><span class="special">,</span> <span class="number">10000</span><span class="special">))</span> <span class="special">;</span>
 118       <span class="identifier">it</span> <span class="special">!=</span> <span class="identifier">tree</span><span class="special">.</span><span class="identifier">qend</span><span class="special">()</span> <span class="special">;</span> <span class="special">++</span><span class="identifier">it</span> <span class="special">)</span>
 119 <span class="special">{</span>
 120     <span class="comment">// do something with value</span>
 121     <span class="keyword">if</span> <span class="special">(</span> <span class="identifier">has_enough_nearest_values</span><span class="special">()</span> <span class="special">)</span>
 122         <span class="keyword">break</span><span class="special">;</span>
 123 <span class="special">}</span>
 124
 125 <span class="comment">// C++11 (auto)</span>
 126 <span class="keyword">for</span> <span class="special">(</span> <span class="keyword">auto</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">tree</span><span class="special">.</span><span class="identifier">qbegin</span><span class="special">(</span><span class="identifier">bgi</span><span class="special">::</span><span class="identifier">nearest</span><span class="special">(</span><span class="identifier">pt</span><span class="special">,</span> <span class="number">3</span><span class="special">))</span> <span class="special">;</span> <span class="identifier">it</span> <span class="special">!=</span> <span class="identifier">tree</span><span class="special">.</span><span class="identifier">qend</span><span class="special">()</span> <span class="special">;</span> <span class="special">++</span><span class="identifier">it</span> <span class="special">)</span>
 127 <span class="special">{</span>
 128     <span class="comment">// do something with value</span>
 129 <span class="special">}</span>
 130
 131 <span class="comment">// C++14 (generic lambda expression)</span>
 132 <span class="identifier">std</span><span class="special">::</span><span class="identifier">for_each</span><span class="special">(</span><span class="identifier">tree</span><span class="special">.</span><span class="identifier">qbegin</span><span class="special">(</span><span class="identifier">bgi</span><span class="special">::</span><span class="identifier">nearest</span><span class="special">(</span><span class="identifier">pt</span><span class="special">,</span> <span class="number">3</span><span class="special">)),</span> <span class="identifier">tree</span><span class="special">.</span><span class="identifier">qend</span><span class="special">(),</span> <span class="special">[](</span><span class="keyword">auto</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">val</span><span class="special">){</span>
 133     <span class="comment">// do something with value</span>
 134 <span class="special">});</span>
 135 </pre>
 136 <p>
 137           </p>
 138 <h6>
 139 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h6"></a>
 140             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.iterator_category"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.iterator_category">Iterator
 141             category</a>
 142           </h6>
 143 <p>
 144             ForwardIterator
 145           </p>
 146 <h6>
 147 <a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.h7"></a>
 148             <span class="phrase"><a name="geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.throws"></a></span><a class="link" href="qbegin_predicates_const___.html#geometry.reference.spatial_indexes.boost__geometry__index__rtree.qbegin_predicates_const___.throws">Throws</a>
 149           </h6>
 150 <p>
 151             If predicates copy throws. If allocation throws.
 152           </p>
 153 <div class="warning"><table border="0" summary="Warning">
 154 <tr>
 155 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../../doc/src/images/warning.png"></td>
 156 <th align="left">Warning</th>
 157 </tr>
 158 <tr><td align="left" valign="top"><p>
 159               The modification of the rtree may invalidate the iterators.
 160             </p></td></tr>
 161 </table></div>
 162 </div>
 163 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 164 <td align="left"></td>
 165 <td align="right"><div class="copyright-footer">Copyright &#169; 2009-2017 Barend
 166       Gehrels, Bruno Lalande, Mateusz Loskot, Adam Wulkiewicz, Oracle and/or its
 167       affiliates<p>
 168         Distributed under the Boost Software License, Version 1.0. (See accompanying
 169         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>)
 170       </p>
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