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swift-mirror/test/expr/cast/nil_value_to_optional.swift
Anthony Latsis 4099e85da6 [Diagnostics & Tests] SR-6052 Prevent nil capitalization (#16256)
And provide better semantic background by surrounding 'nil' in ticks when it is referred to as a value

Added missing tests for certain cases involving nil capitalization
2018-05-03 09:10:30 -07:00

32 lines
907 B
Swift

// RUN: %target-typecheck-verify-swift
var t = true
var f = false
func markUsed<T>(_ t: T) {}
markUsed(t != nil) // expected-warning {{comparing non-optional value of type 'Bool' to 'nil' always returns true}}
markUsed(f != nil) // expected-warning {{comparing non-optional value of type 'Bool' to 'nil' always returns true}}
class C : Equatable {}
func == (lhs: C, rhs: C) -> Bool {
return true
}
func test(_ c: C) {
if c == nil {} // expected-warning {{comparing non-optional value of type 'C' to 'nil' always returns false}}
}
class D {}
var d = D()
var dopt: D? = nil
var diuopt: D! = nil
_ = d! // expected-error {{cannot force unwrap value of non-optional type 'D'}}
_ = dopt == nil
_ = diuopt == nil
_ = diuopt is ExpressibleByNilLiteral // expected-warning {{'is' test is always true}}
// expected-warning@-1 {{conditional cast from 'D?' to 'ExpressibleByNilLiteral' always succeeds}}