Open Radar

 
Summary:
The Swift standard library is missing operators for adding different sized integers.

A developer coming from most other languages would expect integer addition to resize the smaller operand to add correctly, with the expression resulting with the type of the larger operand.

Steps to Reproduce:
Consider this example, throwing an error when adding an Int64 with an Int32.

    let smallNumber: Int32 = 15
    let bigNumber: Int64 = 4294967311

    let total = bigNumber + smallNumber
    // error: could not find an overload for '+' that accepts the supplied arguments


Expected Results:
The expression would resolve to an Int64 with the value of 4294967326, by implicitly resizing the smaller operand.

Actual Results:
There is no operator in the Swift standard library to add two dislike-sized integers.

Adding this custom operator achieves the expected behavior:

    func +(lhs: Int64, rhs: Int32) -> Int64 {
        return lhs + Int64(rhs)
    }
    let total = bigNumber + smallNumber