public protocol P {} public struct S1: P {} public struct S2: P {} public func makePair() -> (some P, some P) { (S1(), S2()) }

// makePair() sil @$s1i8makePairQr_QR_tyF : $@convention(thin) @substituted <τ_0_0, τ_0_1> () -> (@out τ_0_0, @out τ_0_1) for <@_opaqueReturnTypeOf("$s1i8makePairQr_QR_tyF", 0) __, @_opaqueReturnTypeOf("$s1i8makePairQr_QR_tyF", 1) __> {

(edited)