Comment by crazygringo

If you're writing functions for basic mathematical operations, then sure.

But how often is anyone doing that? If you design microprocessors, or programming languages (maybe), or numerical libraries. But hopefully if you do any of those, you already know to test every value against a reference algorithm.

Is there anything in this post that is more generally applicable to the other 99.99% of developers? I'm trying to think of anything I've ever written where it would even be possible to test billions of input values, but there'd never be a reference to test it against.