[Development] Container benchmark was HEADS UP: Don't use QList, use Q_DECLARE_TYPEINFO

[Mark Gaiser]

On Fri, Jul 17, 2015 at 12:07 PM, André Somers <andre at familiesomers.nl>
wrote:

> Marc Mutz schreef op 17-7-2015 om 12:21:
> >
> > What might also be a consideration when making a container like this, is
> > that I find the key is often (not always of course) already part of the
> > value data structure. For instance, if I store employee records and key
> > them by id, that id is also in the record itself. It would be nice to
> > have a fast and friendly key-based container that could handle that
> > without duplicating the data...
> > You can have that with C++11 std::*set, and a custom transparent
> comparator,
> > but of course, they are not cache-friendly. But it's testament to the
> value of
> > having the ability to _have_ a custom comparator. QFashHash consequently
> has
> > that ability, but its a map, not a set, so it won't fit your use-case.
> >
> I guess this [1] would work, but that is C++14, not 11. Otherwise, I
> don't quite see how to retreive my Employee record again if I just have
> the id...
>
> André
>
> [1] http://en.cppreference.com/w/cpp/container/set/find variants 3 and 4
>

You can use std::find_if for that on any container.
Works for C++11 and even before that. C++11 gives the benefit of using a
lambda in the std::find_if UnaryPredicate.
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