stderr

Prints a useful status message.

import core.thread : Thread;
import core.time : dur;

immutable status = `|/-\`;

for (size_t i = 0; ; ++i)
{
    Thread.sleep(dur!"msecs"(100));
    stderr.write("Reticulating splines... ");
    stderr.write([status[i % status.length], '\r']);
    stderr.flush();
}