The idea of constexpr parameters is floated from time to time, but I don't remember any proposals related to them.

The constexpr parameter is a parameter to a function that acts as a constexpr variable (including the possibility to use it as a template argument).

The value of constexpr parameter may influence the return type of the function.

Is anybody working on any such proposal now?

I also remember someone saying that constexpr parameters are incredibly hard to fit into current C++.

However, if we agree that a function with constexpr parameters should be an (implicit) template

(which is hard to swallow, but I don't see any other option...), is it really that difficult?

Regards,

Gregory