File: recursive_superclass.swift

package info (click to toggle)
swiftlang 6.1.3-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 2,791,532 kB
  • sloc: cpp: 9,901,743; ansic: 2,201,431; asm: 1,091,827; python: 308,252; objc: 82,166; f90: 80,126; lisp: 38,358; pascal: 25,559; sh: 20,429; ml: 5,058; perl: 4,745; makefile: 4,484; awk: 3,535; javascript: 3,018; xml: 918; fortran: 664; cs: 573; ruby: 396
file content (44 lines) | stat: -rw-r--r-- 791 bytes parent folder | download 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
// RUN: %target-typecheck-verify-swift

// While we disallow explicitly-stated requirements like
// `T: C<T>`, there are ways to sneak them past the
// diagnostic.
//
// We could relax the diagnostic eventually by rejecting
// the truly invalid cases, where the superclass contains
// a member type of a conformance made redundant by the
// superclass requirement itself.

class C<T> {
  var t: T

  init(t: T) {
    self.t = t
  }
}

protocol P1 {
  associatedtype A: C<B.A>
  associatedtype B: P1
}

func f<T: P1>(_: T, t: T.A) -> C<T.B.B.B.B.A> {
  return t.t.t.t
}

protocol P2 {
  associatedtype A: C<B>
  associatedtype B
}

extension P2 where Self == A {
  func f() -> C<B> {
    return self
  }
}

extension P2 where Self == A, A == B {
  func g() -> C<Self> {
    return self
  }
}