import std.stdio, std.datetime, std.parallelism, core.thread;
 
struct cArr {
 
    int[] Array;
 
    void calc() {
 
        long result = 0;
        foreach (num; Array) {
            Thread.sleep(dur!("msecs")(50));
            result += num;
        }
 
        writeln(result);
    }
}
 
void performMultithreading() {
 
    auto currTime = Clock.currTime();
 
    int[][] arr = [
        [500, 500, 500],
        [500, 500, 500],
        [500, 500, 500],
        [500, 500, 500]
    ];
 
    auto datas = [cArr(arr[0]), cArr(arr[1]), cArr(arr[2]), cArr(arr[3])];
 
    foreach (data; parallel(datas))
        data.calc();
 
    writeln("Duration with multithreading: ", Clock.currTime() - currTime);
}
 
 
void performSinglethreading() {
 
    auto currTime = Clock.currTime();
 
    int[][] arr = [
        [500, 500, 500],
        [500, 500, 500],
        [500, 500, 500],
        [500, 500, 500]
    ];
 
    auto datas = [cArr(arr[0]), cArr(arr[1]), cArr(arr[2]), cArr(arr[3])];
 
    foreach (data; datas)
        data.calc();
 
    writeln("Duration with singlethreading: ", Clock.currTime() - currTime);
}
 
void main() {
 
    performSinglethreading();
    performMultithreading();
}

import std.stdio;
 
void main() {
 
    int[][5] arr;
 
    foreach (i; 0 .. 5)
            arr[i] ~= [i], arr[i] ~= [i + 1];
 
    writeln(arr);   // prints [[0, 1], [1, 2], [2, 3], [3, 4], [4, 5]]
}

import std.stdio;
 
void main() {
 
    int[] a;
 
    a.length = 5;
 
    a[4] = 2;
 
    a.length += 8;
 
    a[12] = 3;
 
    writeln(a);     // prints [0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 3]
 
    a.length /= 2;
 
    writeln(a);     // prints [0, 0, 0, 0, 2, 0]
}

import std.stdio;
import std.traits;
import std.typetuple;
 
void main() {
 
    int val = 99;
    auto a = TypeTuple!("awesome", 2, "dfs", 6, 3 + 10, "bfs", val, 1 - 9, [3, 6, 1]);
 
    foreach (el; a)
        if (is(typeof(el) == int[]))
            writeln(el);        // prints [3, 6, 1]
 
    foreach (el; a)
        if (is(typeof(el) == int))
            el.write(' ');      // prints 2 6 13 99 -8 
 
    writeln;
 
    foreach (el; a)
        if (is(typeof(el) == string))
            el.write(' ');      // prints awesome dfs bfs 
 
    writeln;
}