Re: [Boost-users] Correct use of unordered_map

Subject: Re: [Boost-users] Correct use of unordered_map
From: Nat Goodspeed (nat_at_[hidden])
Date: 2009-08-31 20:56:18

Richard Hadsell wrote:

>> I use one of these 2 ways:
>>
>> for (my_map_t::iterator it= my_map.begin(); it != end; ) {
>>  if (is_to_be_removed(it->first))
>>   it = global_map.erase (it);
>>  else
>>   ++it;
>> }
>>
>> for (my_map_t::iterator it= my_map.begin(); it != end; ) {
>>  my_map_t::iterator itx = it++;
>>  if (is_to_be_removed(itx->first))
>>   global_map.erase (itx);
>> }

> I should add that the second way is useful, when you are not executing 
> 'erase' but rather some arbitrary code that may or may not actually 
> erase the element from the container.

nod

I can't resist pointing out Scott Meyers's "Effective STL," Item 9, p. 
43: "Choose carefully among erasing options."  :-)