Can't Compile Global Semaphores?

[Jack Stouffer via Digitalmars-d-learn]

On Monday, 27 July 2015 at 20:12:10 UTC, John Colvin wrote:
> Yes, but then core.sync.semaphore doesn't support being shared, 
> so...

Ok, so I made the code run by using __gshared instead of shared. 
It seems really odd that a semaphore object doesn't support being 
shared, this that a bug?

Here is the modified code:

import core.sync.semaphore;
import core.thread;
import std.string;
import std.stdio;

__gshared string data;
__gshared Semaphore sem;


void read() {
     data = "From Thread";
     sem.notify();
}


void write() {
     sem.wait();
     data.writeln;
}


void main() {
     sem = new Semaphore();
     Thread reader = new Thread(&read);
     Thread writer = new Thread(&write);

     reader.start();
     writer.start();
}