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// RUN: %target-typecheck-verify-swift -enable-experimental-feature MoveOnlyEnumDeinits
// Typechecking for the discard statement.
func discard() -> Int {}
let x = discard()
discard x // expected-error {{'discard' statement cannot appear in top-level code}}
func `discard`(_ t: Int) {} // expected-note {{'discard' declared here}}
func globalFunc() {
discard x // expected-error {{'discard' statement cannot appear in global function}}
}
class C {
deinit {
discard self // expected-error {{'discard' statement cannot appear in deinitializer}}
}
}
struct S {
static func staticFunc() {
discard x // expected-error {{'discard' statement cannot appear in static method}}
}
var member: Int {
get {
discard x // expected-error {{'discard' statement can only appear in noncopyable type's member}}
}
}
__consuming func f() {
discard self // expected-error {{'discard' statement can only appear in noncopyable type's member}}
}
}
enum E: Error { case err }
@_moveOnly struct File {
let fd: Int
init() throws {
self.fd = 0
discard self // expected-error {{'discard' statement cannot appear in initializer}}
throw E.err
}
init(_ b: Bool) throws {
try self.init()
discard self // expected-error {{'discard' statement cannot appear in initializer}}
throw E.err
}
__consuming func close() {
defer { discard self }
if fd >= 0 {
discard self
return
}
discard self
}
var what: Int {
__consuming get {
discard self
return 0
}
}
__consuming func badClose() {
discard self.fd // expected-error {{you can only discard 'self'}}{{13-20=self}}
// expected-error@-1 {{cannot convert value of type 'Int' to expected discard type 'File'}}
discard Self // expected-error {{you can only discard 'self'}}{{13-17=self}}
// expected-error@-1 {{cannot convert value of type 'File.Type' to expected discard type 'File'}}
discard Self.self // expected-error {{you can only discard 'self'}}{{13-22=self}}
// expected-error@-1 {{cannot convert value of type 'File.Type' to expected discard type 'File'}}
discard self + self // expected-error {{you can only discard 'self'}}{{13-24=self}}
// expected-error@-1 {{binary operator '+' cannot be applied to two 'File' operands}}
// NOTE: I think this error comes from it trying to call discard's subscript
discard [self] // expected-error {{reference to member 'subscript' cannot be resolved without a contextual type}}
discard {} // expected-error {{trailing closure passed to parameter of type 'Int' that does not accept a closure}}
discard (self) // expected-error {{cannot convert value of type 'File' to expected argument type 'Int'}}
// FIXME: we should get an error about it being illegal to discard in a closure.
let _ = { // expected-error {{type of expression is ambiguous without a type annotation}}
discard self
return 0
}()
func hello() {
discard self // expected-error {{'discard' statement cannot appear in local function}}
}
}
deinit {
discard self // expected-error {{'discard' statement cannot appear in deinitializer}}
}
static func staticFunc() {
discard x // expected-error {{'discard' statement cannot appear in static method}}
}
}
@_moveOnly enum FileWrapper {
case valid(File)
case invalid(File)
case nothing
init() throws {
discard self // expected-error {{'discard' statement cannot appear in initializer}}
throw E.err
}
__consuming func take() throws -> File {
if case let .valid(f) = consume self {
return f
}
discard self
throw E.err
}
var validFile: File {
__consuming get {
if case let .valid(f) = consume self {
return f
}
discard self
}
}
deinit {
try? take().close()
}
}
struct NoDeinitStruct: ~Copyable {
consuming func blah() {
discard self // expected-error {{'discard' has no effect for type 'NoDeinitStruct' unless it has a deinitializer}}{{5-18=}}
}
}
enum NoDeinitEnum: ~Copyable {
case whatever
consuming func blah() {
discard self // expected-error {{'discard' has no effect for type 'NoDeinitEnum' unless it has a deinitializer}}{{5-18=}}
}
}
struct HasGenericNotStored<T>: ~Copyable { // expected-note 2{{arguments to generic parameter 'T' ('Int' and 'T') are expected to be equal}}
consuming func discard() { discard self }
consuming func bad_discard1() {
discard HasGenericNotStored<Int>()
// expected-error@-1 {{cannot convert value of type 'HasGenericNotStored<Int>' to expected discard type 'HasGenericNotStored<T>'}}
// expected-error@-2 {{you can only discard 'self'}}
}
consuming func bad_discard2() {
let `self` = HasGenericNotStored<Int>()
discard `self`
// expected-error@-1 {{cannot convert value of type 'HasGenericNotStored<Int>' to expected discard type 'HasGenericNotStored<T>'}}
// expected-error@-2 {{you can only discard 'self'}}{{13-19=self}}
}
func identity(_ t: T) -> T { return t }
deinit{}
}
struct Court: ~Copyable {
let x: Int
consuming func discard(_ other: consuming Court) {
let `self` = other
discard `self` // expected-error {{you can only discard 'self'}}{{13-19=self}}
}
deinit { print("deinit of \(self.x)") }
}
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