var v: Any = 1 if !(v is Bool) { printf("v: %d\n", v as Int) } v = true if v is Bool { printf("v: %s\n", v as Bool ? "true" : "false") } v = Foo(bar: 20, baz: true) if v is Foo { let foo = v as Foo printf("v: Foo(bar: %d, baz: %s)\n", foo.bar, foo.baz ? "true" : "false") } printf("[%s] foo returned\n", #function) printf("%d\n", f) printf("%d\n", duplicate(2) as Int) } 43 — Answering the Existential Question – Samuel Giddins @ FrenchKit 2018