Question

function F() {
    return function() {
        return {};
    }
}

var f = new F();
f instanceof F; // returns false

As far as I understand, if I want instanceof to work, I need to return this from the constructor. But I want the constructor to return a function, and I cannot assign to this.

So, is this really impossible or can it be done somehow, for f = new F() to return a function and still f instanceof F to return true?

Answer 1

function F() {
    var r = function() {
        return {};
    };

    r.__proto__ = this.__proto__;
    return r;
}

var f = new F();
f instanceof F;
true
f();
Object

Only works in the browsers with __proto__