How to create a concept whose functions have type inference?

Question

C++ / C#

I am writing the next concept.

template <typename T>
concept bool Condition = requires(T a) {
    { a.match(...) } -> bool;
};

Quite simple: the concept obliges to have a match method. I want the type of the single match argument to be inferred by itself.
An example of a class that could satisfy such a concept:

class A {
public:
    template <typename T>
    bool match(T&& t) {
        t == 1;
    }
};

Question: how to specify automatic inference of the argument type in the concept? (what should be instead of "..."?)

Answer 1

The concept must be applied to the calling code. I slightly modified your example for the general case. Now they can check if any class contains a match method with a certain signature:

template <class T, class V>
concept bool HasMethodMatch = requires(T a, V v) {
    { a.match(v) } -> bool;
};

class A {
public:
    template <class T>
    bool match(T t) const {
        return t == 1;
    }
};

template <class V> 
    requires HasMethodMatch<A, V>
void doSmth(const A& a, V v)
{
    a.match(v);
}

int main()
{
    A a;
    doSmth(a, 5);
    doSmth(a, 5.f);
    doSmth(a, 5.d);
}

For a more general case, in the doSmth method, class A can be replaced with another template parameter. But, I think the logic is more or less clear now.