On Friday 22 January 2016 17:44:40 Thiago Macieira wrote:
> On Friday 22 January 2016 11:14:47 Marc Mutz wrote:
> > On Friday 22 January 2016 09:57:00 Иван Комиссаров wrote:
> > > What
> > > i'm missing?
> >
> > You haven't done the exercise with the int first.
>
> Here's the exercise with int. This is thread-safe:
>
> int f()
> {
> return 1;
> }
>
> auto x = f();
> ++x;
>
> No matter how many threads call f(), all of them will get a value from f,
> can assign it to a variable and modify without caring what other threads
> do.
>
> Replace int with QMap or QString and you have the same behaviour.
This part of the discussion was about copying a container. You return a new
instance instead. Returning a new instance does not copy, nor move, due to
NRVO.
--
Marc Mutz <marc.m...@kdab.com> | Senior Software Engineer
KDAB (Deutschland) GmbH & Co.KG, a KDAB Group Company
Tel: +49-30-521325470
KDAB - The Qt Experts
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