| // RUN: %target-typecheck-verify-swift |
| |
| precedencegroup BindingPrecedence { |
| higherThan: DefaultPrecedence |
| } |
| |
| infix operator ~> |
| infix operator ≈> : BindingPrecedence |
| |
| struct M<L : P, R> { |
| let f: L |
| let b: (inout L.B) -> R |
| |
| init(f: L, b: @escaping (inout L.B) -> R) { |
| self.f = f |
| self.b = b |
| } |
| } |
| |
| protocol P { |
| associatedtype A |
| associatedtype B |
| |
| func `in`<R>(_ a: inout A, apply body: (inout B) -> R) -> R |
| |
| static func ~> (_: A, _: Self) -> B |
| } |
| |
| extension P { |
| static func ≈> <R>(f: Self, b: @escaping (inout B) -> R) -> M<Self, R> {} |
| // expected-note@-1 {{in call to operator '≈>'}} |
| } |
| |
| extension WritableKeyPath : P { |
| typealias A = Root |
| typealias B = Value |
| |
| func `in`<R>(_ a: inout A, apply body: (inout B) -> R) -> R {} |
| |
| static func ~> (a: A, path: WritableKeyPath) -> B {} |
| } |
| |
| struct X { var y: Int = 0 } |
| var x = X() |
| x ~> \X.y ≈> { a in a += 1; return 3 } |
| // expected-error@-1 {{generic parameter 'R' could not be inferred}} |
| // FIXME: Used to be better: "cannot convert call result type 'M<WritableKeyPath<X, Int>, _>' to expected type 'WritableKeyPath<_, _>'" |
