class A {
  public F[A, B] (_ : A -> B) : void {}
  public G[A] (_ : A) : void {}
  public Q () : void {
    def f (_) {};
    _ = F (f); //E: cannot use `void' in generic specifier 
    _ = G (f (0)); //E: cannot use `void' in generic specifier 
  }
}
class B {
  public static F[A, B] (_ : A -> B) : void {}
  public static G[A] (_ : A) : void {}
  public static Q () : void {
    def f (_) {};
    _ = F (f); //E: cannot use `void' in generic specifier 
    _ = G (f (0)); //E: cannot use `void' in generic specifier 
  }
}
public module FuncHelper2 { 
  public static Pipe[A, B, C] (_fab : A -> B, _fbc : B -> C) : void {
    def d2i ( x : int ) : int { x + 1 }
    def print ( x : int ) : void { System.Console.WriteLine (x) }
    //without void check it generates unverifiable/bad code
    Pipe (d2i, print); //E: cannot use `void' in generic specifier 
  }
}

module Program
{
  Main() : void
  {
    System.Console.WriteLine(Foo((1,2)));
    _ = System.Console.ReadKey()
  }

  Foo(x : object) : string { //E:
   | x is _ * int => //E: cannot use `void' in generic specifier 
        mutable a = x[0];   //E: cannot use `void' in generic specifier 
        a = ();
        "_"
   | _ => "Other"
 }
}

_ = (1, ()); //E: cannot use `void' in generic specifier