ImplicitConverter

A class for implicit values that can serve as implicit conversions The implicit resolution algorithm will act as if there existed the additional implicit definition:

def $implicitConversion[T, U](x: T)(c: ImplicitConverter[T, U]): U = c(x)

However, the presence of this definition would slow down implicit search since its outermost type matches any pair of types. Therefore, implicit search contains a special case in Implicits#discardForView which emulates the conversion in a more efficient way.

Note that this is a SAM class - function literals are automatically converted to ImplicitConverter values.

Also note that in bootstrapped dotty, Predef.<:< should inherit from ImplicitConverter. This would cut the number of special cases in discardForView from two to one.