限制组合隐式参数和视图/上下文范围的原因是什么？

Question

One of the recent commits to Scala master removes restriction on combining context/view bounds with implicit parameters. That's a great improvement that reduces amount of boilerplate, but what was the reason of making that restriction before, and what consequences can we expect now?

Answer 1

Context and view bounds add implicit parameters. So if you write:

def f[T : Manifest](l: List[T])(implicit ord: Ordering[T]) 

There are, in fact, two implicit parameters being passed instead of one. Allowing this kind of syntax will certainly result in some confusion down the road. As implicit parameter usage starts to get more widespread, because of type classes, being able to do something like the above is helpful.