Is it possible to detect whether a class has a member function with a specific name? Note, that the parameter list of the function doesn’t matter, and the function can even be a template function, or the function name can be overloaded.

Detecting whether a member function exists with a known parameter list seems to be easy by using requires:

#include <cstdio>

struct Foo {
    void something(int);
};

template <typename TYPE>
concept has_something = requires(TYPE t) { t.something(42); };

int main() {
    printf("has_something: %dn", has_something<Foo>);
}

But I’d like to detect whether a function exists with any parameter list. If I remove the int parameter from something, has_something will be false.

(I tried to use member pointers in requires, like &TYPE::something;, but it doesn’t work if something is overloaded, as the expression is ambiguous. Not to mention that it doesn’t work with template functions either.)