Simple Generic Function in Kotlin Fails

Question

Here\'s a simple generic function in Kotlin:

fun  twice(x: T) : T { return 2 * x }

Attempting to build this (either in a project or RE

Answer 1

Since T could be anything, the compiler is not able to find a matching times operator. As you can see in the error message, for Int, there a multiple alternatives available

public final operator fun times(other: Byte): Int defined in kotlin.Int
public final operator fun times(other: Double): Double defined in kotlin.Int
public final operator fun times(other: Float): Float defined in kotlin.Int
public final operator fun times(other: Int): Int defined in kotlin.Int
public final operator fun times(other: Long): Long defined in kotlin.Int
public final operator fun times(other: Short): Int defined in kotlin.Int

But unfortunately there's no generic times function, which can be used with e.g. Number. I'm afraid in this case, you would have to create an overload for each type you want to be handling, i.e., Double, Int, etc.