Stdio.write/writeln and flushing

[Somebody via Digitalmars-d]

If i write something like:

writeln("what to do?");
switch(readln[0 .. $ - 1])
{   //..
}
writeln("bye");
...that works just as it should at Windows, started from a 
command prompt. However, if I run it from GNU Emacs, I have to 
manually flush the output after each time I do it before taking 
input, or else the output does not show when it should.

I wonder if write(...) and writeln(...) should automatically 
flush, to enhance portability? Of course, I may be issing missing 
something?