import std.stdio, std.concurrency, core.thread;

void counter(Tid squarer) {
    for (int x = 0;; x++) {
        squarer.send(x);
    }
}

void squarer(Tid printer) {
    while (true) {
        auto x = receiveOnly!int;
        printer.send(x * x);
    }
}

void main() {
    spawn(&counter, spawn(&squarer, thisTid));

    while (true) {
        writeln(receiveOnly!int);
        Thread.sleep(100.msecs);
    }
}