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POSTL map for an struct defined in ANSI C
 

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    <p>I am coding in a mixed C/C++ environment. I have an struct in C part and I would like to collect it in a map container in C++ part. I think I should define a custom <strong>key_compare</strong> function object, and let STL <em>map::insert()</em> orders nodes. However I don't know how can I modify map container to customize <em>map::find()</em> function. I am looking for a way to customize <em>map::find()</em> function to do something more that key_compare function for equivalence checking. </p> <p>Would you please let me know how I can put these functions into STL::map or STL::set ? </p> <p>here is my struct in C part (compile with gcc): </p> <pre><code>typedef struct iotrace_arh_node { double time; unsigned long long int blkno; int bcount; u_int flags; int devno; unsigned long stack_no; } iotrace_arh_node_t; </code></pre> <p>here is my proposed <strong>key_compare</strong> and equivalence checking function for <strong>find()</strong> in the C++ part (compile with g++):</p> <pre><code>int key_compare ( struct iotrace_arh_node tempa, struct iotrace_arh_node tempb ) { return (tempa.blkno-tempb.blkno); } int key_equal( struct iotrace_arh_node tempa, struct iotrace_arh_node tempb ) { if( (tempa.blkno == tempb.blkno) &amp;&amp; (tempa.bcount == tempb.bcount) ) return 0; // tempa and tempb is equal, node fund in the map else if ( (tempb.blkno &lt; tempa.blkno) ) return -1; //tempb is less than tempa else if ( (tempb.blkno &gt;= tempa.blkno) &amp;&amp; ( tempb.blkno + tempb.bcount &lt; tempa.blkno + tempa.bcount) ) return 0; // tempa and tempb is equal, node fund in the map else return 1; //tempb is grater than tempa } </code></pre>
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    1. COpossible duplicate of [Sort Order in STL map and set](http://stackoverflow.com/questions/3370185/sort-order-in-stl-map-and-set)
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