basic_string capacity strategy < 128 characters

[Paolo Carlini]

Joachim Schurig wrote:

> As the standard requires a linear behaviour, and as it was implemented 
> likewise in libstdc++-v2 and lots of code is written expecting such, 
> you might want to rethink the current strategy (or clarify why it was 
> chosen the way it is for -v3).

A quick comment (more later): the standard requires asymptotic (i.e., 
amortized) linear behavior, not linear behavior tout court, and the v3 
strategy for sure guarantees that, since december 2001. See f.i.:

    http://gcc.gnu.org/ml/libstdc++/2001-12/msg00144.html

Paolo.