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package ru.maksim.sample

import org.junit.jupiter.api.Test

class QuickSort {

    @Test
    fun sample() {
        val a = intArrayOf(3, 5, 2, 8, 6, 4)
        quickSort(a, 0, a.lastIndex)

MaksimDmitriev

package ru.maksim.sample

inline fun foo(task: () -> Unit) {
    println("Before task")
    task()
    println("After task")
}

fun callingFunction() {
    foo {

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object ListProcessor {

    fun processStrings(strings: List<Any>) {
        Printer.print(strings)
    }
}

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class Foo<out T : Number>(private val data: T) {

    fun get2(): T {
        return data
    }
}

class Bar<T>(private val data: T) {

    fun get2(): T {

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interface Source<out T> {

    fun nextT(): T
}

class SourceImpl<out T>(private val param: T) : Source<T> {

    override fun nextT(): T {
        return param
    }

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interface Consumer<in T> {

    fun consume(param: T)
}

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interface Consumer<in T> {

    fun put(param: T)
}

class ConsumerImpl<in T> : Consumer<T> {

    override fun put(param: T) {
        println("put param: $param")
    }

MaksimDmitriev

package ru.maksim.sample;

import org.junit.jupiter.api.Test;

import java.util.ArrayList;
import java.util.List;

public class SampleJavaTest {

    @Test

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// Why are Java generics invariant?

// invariant means List<Object> is NOT a parent of List<String>.
// if it was the case, then:

List<String> strs = new ArrayList<String>();
List<Object> objs = strs; // !!! A compile-time error here saves us from a runtime exception later.
objs.add(1); // Put an Integer into a list of Strings
String s = strs.get(0); // !!! ClassCastException: Cannot cast Integer to String

MaksimDmitriev

package ru.maksim.sample

import org.junit.jupiter.api.Test

class ReifiedSampleKotlinTest {

    @Test
    fun foo() {
        val shapeManager = ShapeManager()
        val circle = Circle(10.0)