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b6c3ad3ddc
Add a test for an extremely confusing behavior of switches for ExpressibleByNilLiteral-conforming types. From the looks of the expression tree, one would hope that `case nil` would match such types. Instead, the subject value is up-converted to an optional and compared to `nil` directly with ~=.
31 lines
653 B
Swift
31 lines
653 B
Swift
// RUN: %target-typecheck-verify-swift
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enum Hey {
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case listen
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}
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func test() {
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switch Hey.listen {
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case nil: // expected-warning {{type 'Hey' is not optional, value can never be nil}}
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break
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default:
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break
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}
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}
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struct Nilable: ExpressibleByNilLiteral {
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init(nilLiteral: ()) {}
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}
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func testNil() {
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// N.B. A deeply confusing case as no conversion is performed on the `nil`
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// literal. Instead, the match subject is converted to `Nilable?` and compared
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// using ~=.
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switch Nilable(nilLiteral: ()) {
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case nil: // expected-warning {{type 'Nilable' is not optional, value can never be nil}}
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break
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default:
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break
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}
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}
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