[Boost-bugs] [Boost C++ Libraries] #2484: Const-overload needed for bimap associative_container_adaptor::count()

Subject: [Boost-bugs] [Boost C++ Libraries] #2484: Const-overload needed for bimap associative_container_adaptor::count()
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-11-07 16:48:57

#2484: Const-overload needed for bimap associative_container_adaptor::count()
--------------------------------+-------------------------------------------
 Reporter:  mlcreech_at_[hidden]  |       Owner:  matias 
     Type:  Patches             |      Status:  new    
Milestone:  Boost 1.38.0        |   Component:  bimap  
  Version:  Boost 1.36.0        |    Severity:  Problem
 Keywords:                      |  
--------------------------------+-------------------------------------------
 Would it be possible to include a const-overloaded version of count() for
 associative containers in boost::bimaps?  I had some code like this:

 {{{
 void CMyClass::func(size_t key) const {
        size_t num_elements=_member_map.count(key);
        ...
 }
 }}}

 where _member_map was a std::map, and it worked fine.  When I changed
 _member_map to a bimap, the equivalent code:

 {{{
 void CMyClass::func(size_t key) const {
        size_t num_elements=_member_map.left.count(key);
        ...
 }
 }}}

 gives an error, because count() is non-const (whereas GCC's
 std::map::count() is const).  That's presumably done because the STL
 documentation declares count() as non-const (not sure why), but it doesn't
 seem there would be any harm in adding a const-overload so that this kind
 of code would compile when the underlying type supports it.  The attached
 patch fixes the problem for me.

 Thanks

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2484>
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