What is the best way to use enrich-my-library in scala?

Question

The are two different way to implement it.

One is more short

implicit def toR1(s:String) = new { def getLength = s.length)}

Second is more long

class R2(s:String){def getLength2 = s.length)}
implicit def toR2(s:String) = new R2(s)

Which one is better?

Answer 1

The first version uses a structural type. It makes it possible to write short and readable code, but a disadvantage of structural types is that reflection is used at runtime when you call the method in the structural type. Calling a method via reflection is slower than calling a method directly.

More details are in this blog post (written by me): Avoid structural types when pimping libraries