[Boost-bugs] [Boost C++ Libraries] #11180: has_set_intersection

Subject: [Boost-bugs] [Boost C++ Libraries] #11180: has_set_intersection
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-04-10 10:36:15

#11180: has_set_intersection
------------------------------+-----------------------
 Reporter:  gast128@…         |      Owner:  marshall
     Type:  Feature Requests  |     Status:  new
Milestone:  To Be Determined  |  Component:  algorithm
  Version:  Boost 1.57.0      |   Severity:  Problem
 Keywords:                    |
------------------------------+-----------------------
 We sometimes have the requirement that we are only interested if two
 ranges have overlap. While in general for ranges this is somewhat
 difficult, for sorted ranges it seems easy:

 template<class In1, class In2, class BinaryPredicate>
 bool has_set_intersection(In1 itFirst1, In1 itLast1, In2 itFirst2, In2
 itLast2, BinaryPredicate comp)
 {
     bool bOverlap = false;

     while (itFirst1 != itLast1 && itFirst2 != itLast2)
     {
         if (comp(*itFirst1, *itFirst2))
         {
             ++itFirst1;
         }
         else if (comp(*itFirst2, *itFirst1))
         {
             ++itFirst2;
         }
         else
         {
             bOverlap = true;
             break;
         }
     }

     return bOverlap;
 }

 Ofc this can be achieved with the normal set_intersection as well but that
 loops until the end of one of the ranges and requires an extra output
 iterator functor.

 Maybe an idea?

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11180>
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