Re: Gtk::TreeModel::get_value_vfunc() constness

A cache is a kind of class member data that can very reasonably be declared mutable.
When the cache is changed, the physical state of the owning object changes, but its logical state, as seen by other objects, does not change. That's the kind of data that the mutable keyword is meant for.


2013-10-01 23:38, Dominique Würtz skrev:
I'm implementing a custom Gtk::TreeModel for displaying database query
results. In order to avoid storing the entire result in memory, I'm
using a caching mechanism which stores only those rows in the
neighborhood of recently queried rows. In my get_value_vfunc(), if a
requested row is not in the cache, I need to update my cache.
Unfortunately, the get_value_vfunc() is declared const and thus forbids
mutating my TreeModel object which owns the cache. Any idea how to
resolve this?



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]