[Development] Upgrading the sources to C++11 keywords (Q_NULLPTR, etc.)

Marc Mutz marc.mutz at kdab.com
Tue Feb 10 20:01:43 CET 2015

On Tuesday 10 February 2015 16:33:23 Knoll Lars wrote:
> Not a whole lot? That Atomic COW is around 10% slower than a Plain string
> (does Atomic COW use a fast allocator?) in the use case where you copy
> strings once and modify them in 2/3 of the cases ;-)

I guess the slowdown from -fexceptions is less than 10% and that still sufficed 
to -fno-exceptions most modules. So 10% slowdown is really, really, bad.

And in Qt, we're cheating. We're not marking strings unsharable when we hand 
out references to characters, as we must, to be *implicitly* shared. We're 
only doing "semi-implicit-sharedness", because, let's face it, if we did real-
implicit, we'd be detaching all the time.

Marc Mutz <marc.mutz at kdab.com> | Senior Software Engineer
KDAB (Deutschland) GmbH & Co.KG, a KDAB Group Company
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