Immutable

[harakim via Digitalmars-d-learn]

I am building a system where one thread generates commands and 
sends them to another thread. The commands will never change once 
they are created. I have marked the values immutable, but I've 
been struggling to understand the requirements for sharing a 
variable across threads.

cannot implicitly convert expression (new AppendChatCommand(type, 
text)) of type data.messages.AppendChatCommand to 
immutable(AppendChatCommand)


I'm trying to do this:

immutable(AppendChatCommand) command = new 
AppendChatCommand(type, text);
send(childTid, command); //Compiler does not like command if it's 
not immutable or shared (and I won't be modifying it or using it 
in this thread)

The commands are generated and send as messages to the child. I 
will never even use them again in the parent thread. What is the 
easiest way to do this? Do I need to mark the class somehow?

I can provide a contrived example if necessary.