On Fri, Jul 17, 2015 at 12:07 PM, André Somers <[email protected]> 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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