Newbie problem

[Roger Stokes]

I'd be grateful for advice. The problem is that I can't get the 
example
on page 406-7 of the"The D Programming Language " to compile.
I've cut and pasted the text from the website, and corrected the 
typo (undefined tgt, so use stdout instead).  I get this 
diagnostic:

page406x.d(11): Error: cannot implicitly convert expression 
(__r24.front()) of type ubyte[] to immutable(ubyte)[]

from this input:

import std.algorithm, std.concurrency, std.stdio;

void main() {
   enum bufferSize = 1024 * 100;
   auto tid = spawn(&fileWriter);
   // Read loop
   foreach (immutable(ubyte)[] buffer; stdin.byChunk(bufferSize)) 
{
      send(tid, buffer);
   }
}

void fileWriter() {
   // Write loop
   for (;;) {
      auto buffer = receiveOnly!(immutable(ubyte)[])();
      stdout.write(buffer);
   }
}