How to check if template argument is a callable with a given signature

Question

Basically, what I want to achieve is compile-time verification (with possibly nice error message) that registered callable (either a function, a lambda, a struct with call o

Answer 1

You can use std::is_convertible (since C++11), e.g.

static_assert(std::is_convertible_v>, "Wrong Signature!");

or

static_assert(std::is_convertible_v, "Wrong Signature!");

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