This is such an interesting choice of example because this particular implicit i...

This is such an interesting choice of example because this particular implicit is baked into the language, and the discomfort you feel is a fine measure of how good an idea this is. Last I checked there was no way to turn it off.

  scala> def f(x: Float) = x.round
  f: (x: Float)Int

  scala> f(123456789)
  res0: Int = 123456792

But of course it doesn't stop at converting Ints into Floats.

  scala> f(Long.MaxValue)
  res1: Int = 2147483647

So it seems 9223372036854775807 rounds to 2147483647. This can be a real simplifier if your "big data" is getting too big.