Type parameter can have 'in' or 'out' variance
Reports type parameters that can have in or out variance.
Using in and out variance provides more precise type inference in Kotlin and clearer code semantics.
Example:
class Box<T>(val obj: T)
fun consumeString(box: Box<String>) {}
fun consumeCharSequence(box: Box<CharSequence>) {}
fun usage(box: Box<String>) {
consumeString(box)
consumeCharSequence(box) // Compilation error
}The quick-fix adds the matching variance modifier:
class Box<out T>(val obj: T)
fun consumeString(box: Box<String>) {}
fun consumeCharSequence(box: Box<CharSequence>) {}
fun usage(box: Box<String>) ++{
consumeString(box)
consumeCharSequence(box) // OK
}- By ID
Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.
AddVarianceModifier
Inspection Details | |
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By default bundled with: | |
Can be installed with plugin: | Kotlin, 243.23126-IJ |