Re: Erase in a map

Charles Zhang wrote:
I want to erase items in a map based on some criteria. However, as soon
as the erase is called, iterator become invalid. I would like someone
to tell me the better way to do it.

Here is the source code I am using, and it is crashing.

for ( pos = connectionMap.begin(); pos != connectionMap.end(); ++pos){
ConnectionInfo* conn = pos->second;

if ( current - conn->lastRequestTime > 60 * timeOut ) {
connectionMap.erase(pos);
}
}


To overcome the problem, I start the loop from the beginning after a
item is removed. But this is too slow.

The typically used solution is this:

while(it!=end)
if(predicate(*it))
container.erase(it++);
else
++it;

Note the use of postfix and prefix increment.

Uli


.

Relevant Pages

  • Re: Erase in a map
    ... pos = connectionMap.erase; ... as the erase is called, iterator become invalid. ...
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  • Re: remove an item in a STL list
    ... the sequence becomes invalid. ... The iterator returned by erase() points to ... the returned iterator is invalid. ...
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  • Re: how can I loop a std::list ?
    ... > Siemel Naran wrote: ... the iterator is invalid after the erase. ...
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  • Re: Erase in a map
    ... as the erase is called, iterator become invalid. ... const long current; ...
    (microsoft.public.vc.stl)
  • Re: clear() on vectors
    ... >> i am trying to write a vector class that includes a erase and clear ... >>without copying and ammending the header file. ... >> clearcalled the 2 iterator erase function, ...
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