Can I use a function typedef in function definitions?

I've defined:

typedef int FunkyFunc(int x);

Now, I would like to be able to use this typedef in the definition of functions of type FunkyFunc, e.g.

FunkyFunc f {
    return 2*x;
}

or

FunkyFunc f(int x) {
    return 2*x;
}

or

FunkyFunc f(x) {
    return 2*x;
}

can I do something similar to any of the above? None of them seems to compile.