[lbriner]

I never quite got it. We used it for a number of things back in the late 90s but to have all of the condition checking enabled made it run much slower, which was like most other languages at the time, you tested in debug and then released it in release mode.

Also, in reference to Ariane rocket explosion (https://en.wikipedia.org/wiki/Ariane_flight_V88) due to interger overflow, it wasn't clear how a precondition would have saved anything - an assertion made by Meyer. If it got to the relevant method and the precondition failed, you would still have to have forseen the possibility of error and coded for it, otherwise it might not have run the function but could still have catastrophically failed.