Re: [Boost-users] Boost or Standard when there is the choice?

Subject: Re: [Boost-users] Boost or Standard when there is the choice?
From: Niall Douglas (s_sourceforge_at_[hidden])
Date: 2014-02-17 11:33:19

On 16 Feb 2014 at 17:34, Joaquin M Lopez Munoz wrote:

> > Also, performance isn't everything, memory footprint is also very 
> > important. It's unfortunate that blog didn't show differences in 
> > unordered_map<> memory consumption. I'd warrant that Dinkumware's 
> > unordered_map<> is very, very good on memory footprint. For the other 
> > STLs, I wouldn't like to guess.
> 
> The overhead (memory minus sizeof(value_type)) in words for a container
> of N elments and B buckets is: 
> 
> * Dinkum: 2B + 2N
> * libstdc++: 1B + 2N (1B + 1N is hash is fast and does not throw)
> * libc++: 1B + 2N
> * Boost.Unordered
>   - unique elements: 1B + 2N
>   - duplicate elements: 1B + 3N
> * Boost.MultiIndex: 1B + 2N
> 
> So, in fact Dinkumware and Boost.Unordered-duplicate are
> the ones that use the most memory.

I have to admit I am surprised that Dinkumware would be an outlier 
here. But I'm no expert, I was simply judging from fairly fuzzy 
indirect benchmarking. Thanks for the detail Joaquín, it was usefully 
informative.

Niall

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