Nested classes or structs cannot use protocols in methods

[xx-li (Stellar)]

class Test {
    func test() {
        struct NestedTest: Comparable {
            static func < (lhs: NestedTest, rhs: NestedTest) -> Bool {
                return false;
            }
            static func == (lhs: NestedTest, rhs: NestedTest) -> Bool {
                return false;
            }
        }
    }
}

error: Type 'NestedTest' does not conform to protocol 'Comparable'

Is it a bug or does not support this?

[anthonylatsis]

The fourth time this is asked about this week; apparently a recently introduced issue. Here's the SR-8696

Type scope operators doesn't work if type is declared in function scope, bug?

(I've only tested this in Xcode 10 b6) This program compiles and works as expected: struct S { var v: Int static func +(lhs: S, rhs: S) -> S { return S(v: lhs.v + rhs.v) } } func foo() { print(S(v: 123) + S(v: 456)) // 579 } foo() But this program produces an unexpected compile time error: func foo() { struct S { var v: Int static func +(lhs: S, rhs: S) -> S { return S(v: lhs.v + rhs.v) } } print(S(v: 123) + S(v: 456)) // ERROR: Binary operator '+' can…

Nested struct Comparable conformance not working?

why does this not work when the struct is local to a function? func f() { struct Pair:Hashable, Comparable { let x:Int, y:Int static func < (lhs:Pair, rhs:Pair) -> Bool { if lhs.y < rhs.y { return true } else if lhs.y == rhs.y { return lhs.x < rhs.x } else { return false } } …

Hashable struct in function

Hello ! I would like to have some clarifications about why Set does not interact properly with a Hashable struct declared in a function. Here I have a struct Hello that conforms to hashable and only needs its id for the hashValue. Because structs need to have Equatable custom conformance to have custom hash behavior, so a == function is declared. 23 I first declare a Set with an identifier 123 and the I try to insert another struct having the same identifier with different "value". It does not…

[xx-li (Stellar)]

Thank you for your answer. I want to try the sample you provided, but can't compile？How to get the output you gave？

[taylorswift]

@anthonylatsis

The fourth time this is asked about this week

why wasn’t this caught in the source compatibility suite?

[anthonylatsis]

Types nested in functions that explicitly conform to protocols with an operator function requirement is quite the specific case, I'm not surprised there isn't a compiler test for that. Regarding the source compatibility suite, it could be that the changes in the PR that introduced the bug didn't require testing source compatibility. But I can't be sure there is an appropriate test in the source compatibility suite either; that might also be the case, assuming there is high probability that the source compatibility tests were run at least once after introducing the bug.

[jrose (Jordan Rose)]

I'm pretty sure there's no test for it because it has never worked. I'm not sure why it's getting so much attention right now.