How to define the type of a named function?

Question

function Foo(): string {}

Means a Foo is a function that returns a string.

interface SFC {
    (props: Props): any;
}

const Foo: SFC = p => {};

Means that Foo is an anonymous function matching the signature SFC and p is of type Props.

How can I declare function Foo() that matches SFC? What's the syntax?

i.e., I want to declare a function using the function keyword (not const) and the function itself is of type SFC.

---

These don't work:

function Foo: SFC () {}
function Foo() {}: SFC

Answer 1

TypeScript uses duck typing, so the Foo function is of type SFC if their structure matches.

interface SFC {
    (props: any): any;
}

function Foo(props: any): any {
    console.log(props);
}

let sfc: SFC = Foo; // Foo is of type SFC.
sfc("Foo");