Better polymorphic ducks

In a previous post we discussed how to combine duck typing with runtime polymorphism. A polymorphic duck if you will. Today let’s see how we can improve on our original design to remove some limitations.

The use of the TEPS (Type Erasure (Sean) Parent Style) we have shown in the first part of this series gave us what I call a Polymorphic Duck: something that can walk like a duck and quack like a duck, but it not necessarly inherited from a base Duck class. Moreover, the quack() and walk() are expected to be free function, not methods, which allows for looser coupling (especially if they take arguments that have nothing to do with the duck itself).

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Polymorphic ducks

It’s no secret C++ favours static polymorphism. But sometimes, runtime polymorphism is needed and suddenly we find ourselves down the virtual rabbit hole. Do not despair, for there are ways to avoid this madness.

I hate the virtual keyword. Inheritance fills me with a sense of dread. I can always quote half a dozen technical reasons to explain it. People much more smarter than me have discussed why it’s the worst form of composition.

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Meeting C++ 2017 trip report

I was at Meeting C++ 2017 to give a talk and then relax while listening to other speakers. That didn’t go exactly as planned.

About 6 months ago, I sent the abstract of one of my submissions to CppCon to my colleague Jonathan Boccara for advice. A few messages in the discussion he asks “did you also submit for Meeting C++?” and I admitted the thought hadn’t crossed my mind. To me, speaking at one conference like CppCon was already a big step and it would be redundant to propose the same talk at two different conferences anyway.

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About leaky abstractions

There is one kind of leak that neither RAII nor garbage collection can fix, it’s abstraction leaks. The idea was coined by Joel Spolsky back in 2002 and remains one of my favourite computer science article.

The law of leaky abstractions by Joel Spolsky is one of the first technical article I encountered after I got my engineering degree and it remains one of the most influential to me.

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