Re: Sending an immutable object to a thread

[Ali Çehreli via Digitalmars-d-learn]

It is a pitty that although Variant is the default message type in 
concurrency, it still has issues:

https://issues.dlang.org/buglist.cgi?quicksearch=variant%20concurrency&list_id=202195

It looks like passing a pointer to an immutable(Message) works as well:

import std.stdio;
import std.concurrency;

class Message
{
    int i;

    this(int i) immutable
    {
        this.i = i;
    }
}

int do_something_with(immutable(Message) msg)
{
    writefln("msg.i is %s", msg.i);
    return 0;
}

void threadFunc()
{
    receive((Tid cli, immutable(Message) *msg) {
            int retCode = do_something_with(*msg);
            send(cli, retCode);
        });

    ownerTid.send(42);
}


void main()
{
    auto msg = new immutable(Message)(100);

    Tid tid = spawn(&threadFunc);
    send(tid, thisTid(), &msg);    // <-- POINTER
    receiveOnly!int();
}

Ali