Re: [boost] [utility] new auto_buffer class --- RFC

Subject: Re: [boost] [utility] new auto_buffer class --- RFC
From: Peter Dimov (pdimov_at_[hidden])
Date: 2009-03-02 12:56:51

Thorsten Ottosen:
> Peter Dimov skrev:
...
>> for x in w
>>    if pred(x)
>>        v.push_back(x)
>>
>> The typical number of elements satisfying pred may be ~7.1, so making v 
>> have a stack capacity of 8 will eliminate a heap allocation and will be a 
>> big win. But you can't determine the maximum capacity in advance.
>
> Is it not |w|?

Yes, it technically is bounded by |w|. But using |w| as the capacity of v 
defeats the purpose of the optimization, which is to avoid allocating 
storage for |w| elements (typically on the heap).