While that's true for fixed-precision integer arithmetic, this doesn't hold true for floating point multiplication.
243 karma · joined February 17, 2014
I'd be quite interested in seeing a benchmark comparing checked and unchecked addition that doesn't get auto-vectorized to understand the performance in practice for non-numerical computing.
As for your warfare speculation, I am happy to say it is just that. We have not had any warfare whatsoever here at Coursera. That simply is not our style. Instead, we tried out a variety of different programming languages. Through organic internal growth, we have come to adopt Scala and Play! not because of a decree but because we have found it helps us get the most done quickly, and reliably.