我遇到了一个问题,最好用代码来表达--下面是一个简化的例子: abstract class MainTC[A] {
type E
// A type constructor for the implementing type:
type CN[_]
implicit val ev: CN[A] =:= A // check that CN works as a type constructor for A
def get(self: A): E
def set[B](self: A, other: B): CN[B] { type E = B }
def c