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// RUN: %target-typecheck-verify-swift
class Base : Hashable {
func hash(into hasher: inout Hasher) {}
}
class Derived : Base { }
func ==(lhs: Base, rhs: Base) -> Bool { return false }
func ..<(x: Int?, y: Int) -> Int? { return x }
// Inputs that are more optional than the output.
func f1(i: Int?, ii: Int??, a: [Base]?, d: [Base : Base]?, de: Derived?) {
_ = i as! Int // expected-warning{{forced cast from 'Int?' to 'Int' only unwraps optionals; did you mean to use '!'?}}{{8-8=!}}{{8-16=}}
_ = ii as! Int // expected-warning{{forced cast from 'Int??' to 'Int' only unwraps optionals; did you mean to use '!!'?}}{{9-9=!!}}{{9-17=}}
_ = a as! [Base] // expected-warning{{forced cast from '[Base]?' to '[Base]' only unwraps optionals; did you mean to use '!'?}}{{8-8=!}}{{8-19=}}
_ = d as! [Base : Base] // expected-warning{{forced cast from '[Base : Base]?' to '[Base : Base]' only unwraps optionals; did you mean to use '!'?}}{{8-8=!}}{{8-26=}}
_ = de as! Base // expected-warning{{forced cast from 'Derived?' to 'Base' only unwraps optionals; did you mean to use '!'?}}{{9-9=!}}{{9-18=}}
// Conditional casts
_ = i as? Int // expected-warning{{conditional downcast from 'Int?' to 'Int' does nothing}}{{8-16=}}
_ = ii as? Int
_ = a as? [Base] // expected-warning{{conditional downcast from '[Base]?' to '[Base]' does nothing}}{{8-19=}}
_ = d as? [Base : Base] // expected-warning{{conditional downcast from '[Base : Base]?' to '[Base : Base]' does nothing}}{{8-26=}}
_ = de as? Base // expected-warning{{conditional downcast from 'Derived?' to 'Base' is equivalent to an implicit conversion to an optional 'Base'}}{{9-18=}}
// "is" checks
_ = i is Int // expected-warning{{checking a value with optional type 'Int?' against type 'Int' succeeds whenever the value is non-nil; did you mean to use '!= nil'?}}{{9-15=!= nil}}
_ = i..<1 is Int // expected-warning{{checking a value with optional type 'Int?' against type 'Int' succeeds whenever the value is non-nil; did you mean to use '!= nil'?}}{{7-7=(}}{{12-12=)}}{{13-19=!= nil}}
_ = ii is Int
_ = i..<1 is Bool // expected-warning{{cast from 'Int?' to unrelated type 'Bool' always fails}}
}
func implicitCastOfLiteralToOptional() {
var _: Int? = 0
var _: String? = ""
var _: [Int] = []
var _: [Int : Int]? = [:]
var _: Set<Int> = []
}
// A nil value can be cast to any other optional type.
// https://github.com/apple/swift/issues/46093
func castUnrelatedOptionalTypes(x: Int?) {
let _ = x as String? // expected-error {{cannot convert value}}
// expected-note@-1 {{arguments to generic parameter 'Wrapped' ('Int' and 'String') are expected to be equal}}
let _ = x as? String? // no-warning
}
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