kateinoigakukun

struct A<T1, T2> {} typealias B<T> = A<Int, T> typealias D = A<Int, Int> protocol C {} extension A: C where T1 == Int {}

Version:

swift-4.0.3-RELEASE

Output:

Error:

/usercode/main.swift:7:1: error: extension of type 'A' with constraints cannot have an inheritance clause extension A: C where T1 == Int {} ^ ~