Generics

Type Constraints

Require a generic value to provide a known operation.

Type Constraints

TypeConstraints.kt 
interface HasCode {
    fun code(): String
}

class Product(val prefix: String) : HasCode {
    override fun code(): String {
        return "$prefix-1"
    }
}

fun <T : HasCode> codeLabel(item: T): String {
    val code = item.code()
    return "code:$code"
}

fun main() {
    val prefix = 
    val product = Product(prefix)
    val label = codeLabel(product)

    println("prefix=$prefix")
    println("label=$label")
}

interface HasCode {
    fun code(): String
}

class Product(val prefix: String) : HasCode {
    override fun code(): String {
        return "$prefix-1"
    }
}

fun <T : HasCode> codeLabel(item: T): String {
    val code = item.code()
    return "code:$code"
}

fun main() {
    val prefix = 
    val product = Product(prefix)
    val label = codeLabel(product)

    println("prefix=$prefix")
    println("label=$label")
}

interface HasCode {
    fun code(): String
}

class Product(val prefix: String) : HasCode {
    override fun code(): String {
        return "$prefix-1"
    }
}

fun <T : HasCode> codeLabel(item: T): String {
    val code = item.code()
    return "code:$code"
}

fun main() {
    val prefix = 
    val product = Product(prefix)
    val label = codeLabel(product)

    println("prefix=$prefix")
    println("label=$label")
}
type-constraint A type constraint lets generic code call members promised by an interface or superclass.