[Fwd: basic_string<> - useless because of its poor performance]

[Nathan Myers]

Loren James Rittle wrote:
> Ryszard Kabatek <Ryszard.Kabatek@softax.pl> writes:
> 
> > The current implementation of basic_string is too slow to be useful.
> 
> Only if you fail to use reserve() wisely as suggested by Stroustrup... ;-)

No.  The standard says that string growth is "amortized linear".
 
> I do basically agree that we should do something better than
> per-character growth given what we generally know about malloc
> implementations.  However, it is unclear that an exponential growth
> policy is wise.

An exponential growth policy is the only way to get the performance
required by the standard.  In fact, exponential growth with base 2
is required by the wording, although there have been suggestions that 
1.5 should be allowed in future amendments.

Nathan Myers
ncm at cantrip dot org