Description
class NumberWrapper {
constructor(private value: number) {}
valueOf(): number { return this.value; }
}
var x = new NumberWrapper(1);
// The right-hand side of an arithmetic operation
// must be of type 'any', 'number' or an enum type.
console.log(2 + x);It would be nice if an arithmetic operation could allow using the wrapped number because it's valueOf() method returns the expected primitive type.
This can be generalized to: if type T is expected, then a value that implements the following interface can be used.
interface Wrapped<T> {
valueOf(): T;
}