Using two types with one template definition

Question

Is it possible to use two different types, one is a subtype of the other, with one template definition?

Something like:

template<typename T>
void foo(T a, T::bar b);

Sorry if there is a duplicate already. I couldn't find one for hours — Petar Velev, Oct 22 '21 at 16:08

score 2 · Accepted Answer · answered Oct 22 '21 at 16:09

2

You would need one more usage of typename

template <typename T>
void foo(T a, typename T::bar b);

because bar is a "dependent type" of T. See here for more details.

answered Oct 22 '21 at 16:09

Cory Kramer

So easy :), Can you define it as `template ` ? – Petar Velev Oct 22 '21 at 16:22
1

@PetarVelev: yes.. but it would not have identical meaning, and default would mostly be useless as `T2` would be deduced from argument. – Jarod42 Oct 22 '21 at 16:33
Yes. I know that the types can be deducted from the arguments. Maybe I could've used a better example. I was trying to make it as minimal as possible – Petar Velev Oct 22 '21 at 16:35

1 Answers1