[peq]

I think implicit conversions were added originally to support Java compatibility without boilerplate code.

It then turned out that they could be used to simulate extension methods, which is probably the main use case for implicit classes in Scala2.

And implicit parameters were probably just the result of trying to make type classes modular.

The CanBuildFrom approach came later than implicit parameters (https://stackoverflow.com/questions/1722726/is-the-scala-2-8...).