Re: [Boost-Users] Newbie boost::bind problem

From: Mark Snelling (mark_at_[hidden])
Date: 2002-09-12 15:27:02

Ok, I understand the following:
std::for_each(mylist.begin(),mylist.end(),boost::checked_deleter<Object>());

But when I try to use the boost::checked_deleter on the objects held in 
a map using your solution to my first problem I don't seem to be able to 
get it to compile:

template<class It, class F> void for_each_pair(It first, It last, F f)
{
     for(; first != last; ++first)
     {
         f(first->first, first->second);
     }
}

int main()
{
     std::map<int, Block*> blocks;
     std::for_each_pair(blocks.begin(), blocks.end(),
         boost::bind(boost::checked_delete<Block>(), _2));
}

Mark.

Peter Dimov wrote:
> From: "Mark Snelling" <mark_at_[hidden]>
> [...]
> 
>>std::list<Object*> mylist;
>>
>>I can call the for_each algorithm on this list using my function above:
>>
>>std::for_each(mylist.begin(), mylist.end(), &deleter);
>>
>>and it will delete all of the objects pointed to in the list.
>>Is it possible to convert deleter into a templated function:
>>
>>template<class T> void deleter(T* t)
>>{
>>    delete t;
>>}
>>
>>and pass that into the for_each algorithm?
> 
> 
> Yes. You can use
> 
> std::for_each(mylist.begin(), mylist.end(), &deleter<Object>);
> 
> If this doesn't work, try
> 
> #include <boost/checked_delete.hpp>
> 
> std::for_each(mylist.begin(), mylist.end(),
> boost::checked_deleter<Object>());
> 
> An alternative is to convert mylist to
> 
> std::list< boost::shared_ptr<Object > mylist;
> 
> and let it worry about the lifetime of the objects.
> 
> 
> 
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