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// RUN: %target-typecheck-verify-swift -enable-experimental-feature ThenStatements
// Required for experimental features
// REQUIRES: asserts
enum E {
case e
case f
case g(Int)
}
func testVoidNeverConversion() {
// Explicit 'then' statements don't participate in implicit Void/Never conversions.
let _: () -> Void = {
if .random() {
then 0 // expected-error {{cannot convert value of type 'Int' to specified type 'Void'}}
} else {
0
}
}
let _: () -> Void = {
if .random() {
then fatalError() // expected-error {{cannot convert value of type 'Never' to specified type 'Void'}}
} else {
0
}
}
let _ = {
if .random() {
then "" // expected-error {{branches have mismatching types 'String' and 'Int'}}
} else {
then 0
}
}
let _ = {
if .random() {
then ()
} else {
0 // expected-warning {{integer literal is unused}}
}
}
let _ = {
if .random() {
then ""
} else {
fatalError()
}
}
func foo() -> Int {
switch Bool.random() {
case true:
fatalError()
case false:
then fatalError() // expected-error {{cannot convert value of type 'Never' to specified type 'Int'}}
}
}
}
enum Either<T, U> {
case first(T), second(U)
}
@resultBuilder
struct Builder { // expected-note 2{{struct 'Builder' declared here}}
static func buildBlock<T>(_ x: T) -> T { x }
static func buildBlock<T, U>(_ x: T, _ y: U) -> (T, U) { (x, y) }
static func buildEither<T, U>(first x: T) -> Either<T, U> { .first(x) }
static func buildEither<T, U>(second x: U) -> Either<T, U> { .second(x) }
static func buildExpression(_ x: Double) -> Double { x }
static func buildExpression<T>(_ x: T) -> T { x }
}
@Builder
func testThenStmtBuilder1() -> Either<Int, Int> {
// We don't allow explicit 'then' to be part of the transform.
if .random() {
then 0 // expected-error {{closure containing control flow statement cannot be used with result builder 'Builder'}}
} else {
1
}
}
@Builder
func testThenStmtBuilder2() -> Either<Int, Int> {
// We don't allow explicit 'then' to be part of the transform.
if .random() {
then 0 // expected-error {{closure containing control flow statement cannot be used with result builder 'Builder'}}
} else {
1
}
()
}
@Builder
func testThenStmtBuilder3() -> Either<Int, String> {
// But it's fine as part of e.g a binding.
let x = if .random() {
then 0
} else {
1
}
if .random() {
x
} else {
""
}
}
|
