Re: [ublas] max_size in vector?

From: Michael Stevens (mail_at_[hidden])
Date: 2005-09-28 20:28:19

On Wednesday 28 Sep 2005 22:49, Shawn D. Pautz wrote:
> Here's another concept conformance issue, although it's possible that
> it's a compiler issue.  According to the documentation for the Vector
> concept a call to resize with a preserve value of false should yield a
> vector "in the same state as that after an equivalent sizing
> constructor".  This does not appear to be the case, at least for
> ublas::vector and bounded_vector, if "same state" means "same values".

In this case "in the same state as that after an equivalent sizing
constructor" means that

ublas::vector<double> vec;
 // any changes to vec
vec.resize(N);

is semantically equivilient to 
   ublas::vector<double> vec(N);

In the case ublas::vector and bounded_vector this means that the values become 
undefined. I not sure of a better way to express this.

The definitition is intentionally tied to that of the sizing constructor. In 
the case of sparse types they can give a zeroing guarantee for the sizing 
constructor (and resize) at no runtime cost.

Michael
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Michael Stevens Systems Engineering
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