[raumpolizei]

Merry Christmas everyone,

from time to time, by going through the OF code (v16.12), I see some crazy (to me) inheritance hierarchies combined with multiple inheritance. One example is the class template reactingMixture (src/thermophysicalModels/reactionThermo/mixtures/reactingMixture):

template<class ThermoType>
class reactingMixture
:
    public speciesTable,
    public autoPtr<chemistryReader<ThermoType>>,
    public multiComponentMixture<ThermoType>,
    public PtrList<Reaction<ThermoType>>
{
    // ...
    // declarations
    // ...
};

I've learned that public inheritance can be understood as "is a" relationship (here reactingMixture<ThermoType> is a autoPtr<chemistryReader<ThermoType>>, for instance). The previously posted code does not seem to fit this principle, as the "is a" criterion does not fit for most of these base classes.

My question: Is there a reason for that (some kind of paradigm I do not know about)? What are the advantages of such design? I thought that usually this kind of problem would be solved through composition. Am I just not seeing the big picture?

Thanks for your answers
RP

[olesen]

You are probably right that the reader could/should be a member composition instead of inheritance (although I don't have the code in front of me at the moment). Please open a gitlab issue to track and discuss this.
Thanks,
/mark

[olesen]

filed as https://develop.openfoam.com/Develop...us/issues/1144

[raumpolizei]

Thanks Mark