> On Jun 17, 2017, at 20:43, Xiaodi Wu <[email protected]> wrote:
>
> In Swift, all types and all operators are implemented in the standard
> library. How do you express the idea that, when you add values of disparate
> types T and U, the result should be of the type with greater precision? You
> need to be able to spell this somehow.
Oh, ok... I thought you meant "conditional conformance" or something concrete
:-D
Off the top of my head, with "literals as generic parameters",
protocol Addable {
associatedtype BitsOfPrecision: IntegerLiteral
static func + <T: Addable> (_: Self, _: T) -> T where T.BitsOfPrecision >
BitsOfPrecision
static func + <T: Addable> (_: Self, _: T) -> Self where T.BitsOfPrecision <=
BitsOfPrecision
}
Although, come to think of it, I suppose that's a bit more than simply using
literals as types. Still, it's all information that's available at compile
time, though.
- Dave Sweeris _______________________________________________
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