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deallocate allocated memory

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Join Date: Jul 2009

Posts: 57

Reputation: atch is an unknown quantity at this point

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atch

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Junior Poster in Training

deallocate allocated memory

Oct 2nd, 2009

Hi,
I'm trying to implement my own allocator using malloc and free. One thing what interests me is that in declaration of deallocate in addition to pointer we have also parameter size which suppose to be size of elements allocated with allocate but having implemented my deallocate as this:

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template<typename T>
void Allocator<T>::deallocate(pointer p, size_type n)
{
     free(p);
}
template<typename T>
void Allocator<T>::deallocate(pointer p, size_type n)
{
     free(p);
}

I have no idea for what I should use this (size_type) parameter.
Looking forward to your reply.
Thank you.

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Join Date: Jun 2009

Posts: 681

Reputation: Tom Gunn has much to be proud of

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Tom Gunn

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Practically a Master Poster

Re: deallocate allocated memory

Oct 2nd, 2009

•

I have no idea for what I should use this (size_type) parameter.

If your allocator does not need it, do not worry about it. The allocator interface was designed to be generic, and some allocators will need that information to manage the memory. For example, moving blocks from a 'used' pool to a 'free' pool means knowing how many blocks to move. Or more simply, the size could be used for debug information.

-Tommy (For Great Justice!) Gunn