P.S. Compiling my program with `ldc -O2`, it runs so fast that I couldn't measure any meaningful running time that's greater than startup overhead. So I wrote a helper program to generate random phone numbers up to 50 characters long, and found that it could encode 1 million phone numbers in 2.2 seconds (using the 75,000 entry dictionary from your repository). Counting vs. printing the results made no significant difference to this.
T -- People tell me that I'm skeptical, but I don't believe them.
