Andrey Breslav
41 lines
1.4 KiB
Kotlin
41 lines
1.4 KiB
Kotlin
package variance
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abstract class Consumer<in T> {}
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abstract class Producer<out T> {}
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abstract class Usual<T> {}
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fun foo(c: Consumer<Int>, p: Producer<Int>, u: Usual<Int>) {
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val c1: Consumer<Any> = <!TYPE_MISMATCH!>c<!>
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val <!UNUSED_VARIABLE!>c2<!>: Consumer<Int> = c1
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val p1: Producer<Any> = p
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val <!UNUSED_VARIABLE!>p2<!>: Producer<Int> = <!TYPE_MISMATCH!>p1<!>
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val u1: Usual<Any> = <!TYPE_MISMATCH!>u<!>
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val <!UNUSED_VARIABLE!>u2<!>: Usual<Int> = <!TYPE_MISMATCH!>u1<!>
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}
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//Arrays copy example
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class Array<T>(val length : Int, val t : T) {
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fun get(<!UNUSED_PARAMETER!>index<!> : Int) : T { return t }
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fun set(<!UNUSED_PARAMETER!>index<!> : Int, <!UNUSED_PARAMETER!>value<!> : T) { /* ... */ }
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}
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fun copy1(<!UNUSED_PARAMETER!>from<!> : Array<Any>, <!UNUSED_PARAMETER!>to<!> : Array<Any>) {}
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fun copy2(<!UNUSED_PARAMETER!>from<!> : Array<out Any>, <!UNUSED_PARAMETER!>to<!> : Array<in Any>) {}
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fun <T> copy3(<!UNUSED_PARAMETER!>from<!> : Array<out T>, <!UNUSED_PARAMETER!>to<!> : Array<in T>) {}
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fun copy4(<!UNUSED_PARAMETER!>from<!> : Array<out Number>, <!UNUSED_PARAMETER!>to<!> : Array<in Int>) {}
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fun f(ints: Array<Int>, any: Array<Any>, numbers: Array<Number>) {
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copy1(<!TYPE_MISMATCH!>ints<!>, any)
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copy2(ints, any) //ok
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copy2(ints, <!TYPE_MISMATCH!>numbers<!>)
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copy3<Int>(ints, numbers)
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copy4(ints, numbers) //ok
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}
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