Re: [boost] [poly_collection] Request for comments: fast polymorphic collections

Subject: Re: [boost] [poly_collection] Request for comments: fast polymorphic collections
From: Joaquin M López Muñoz (joaquinlopezmunoz_at_[hidden])
Date: 2016-11-19 04:09:43

El 18/11/2016 a las 11:56, Thorsten Ottosen escribió:
> It also seems natural to expect that capacity() - size() for a 
> container to tell us the number of elements I can insert without 
> reallocation will happen, and hence is important if one want to reason 
> about exception-safety. With the exotic definition of capacity() that 
> is no longer the case.

Here I don't see an alternative: please note that c.insert(x) can 
*never* guarantee no memory allocation because x can be of an as-of-yet 
unregistered type, which will force the creation of a new segment etc. 
So, we can only provide capacity information for *registered* types, 
which is precisely what the exotic definition of capacity() does. Do you 
see any other viable definition?

Joaquín M López Muñoz