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POSyntax for finding structs in multisets - C++
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  1. POSyntax for finding structs in multisets - C++
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    copied!<p>I can't seem to figure out the syntax for finding structs in containers.</p> <p>I have a multiset of <code>Event</code> structs. I'm trying to find one of these structs by searching on its key. I get the compiler error commented below.</p> <pre><code>struct Event { public: bool operator &lt; ( const Event &amp; rhs ) const { return ( time &lt; rhs.time ); } bool operator &gt; ( const Event &amp; rhs ) const { return ( time &gt; rhs.time ); } bool operator == ( const Event &amp; rhs ) const { return ( time == rhs.time ); } double time; int eventID; int hostID; int s; }; typedef std::multiset&lt; Event, std::less&lt; Event &gt; &gt; EventPQ; EventPQ currentEvents; double oldRecTime = 20.0; EventPQ::iterator ceItr = currentEvents.find( EventPQ::key_type( oldRecTime ) ); // no matching function call </code></pre> <p>I've tried a few permutations to no avail. I thought defining the conditional equality operator was going to be enough.</p> <hr> <p><strong>Solution</strong></p> <p>After correcting my typo (sorry), I now have a solution closest to AraK's, augmented by Soapbox's suggested use of <code>explicit</code>:</p> <pre><code>struct Event { explicit Event(double t) : time(t), eventID(), hostID(), s() {} Event(double t, int eid, int hid, int stype) : time(t), eventID( eid ), hostID( hid ), s(stype) {} ... }; EventPQ::iterator ceItr = currentEvents.find( EventPQ::key_type( Event(oldRecTime) ) ); </code></pre> <p>I recently discovered that another option would have been to use <code>find_if</code>, discussed <a href="https://stackoverflow.com/questions/589985/vectors-structs-and-stdfind">here</a>.</p> <p>Thanks for the help.</p>
 

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