Open
Description
class Bippy[A](val value: A) extends AnyVal
trait Foo[A] {
def m(x: A): Int
}
trait Bar[A] extends Foo[A] {
def m(x: A): Int
}
object Main {
def create[A] = new Bar[Bippy[A]] { def m(x: Bippy[A]) = 0 }
def main(args: Array[String]): Unit = create[Int]
}java.lang.ClassFormatError: Duplicate method name&signature in class file Main$$anon$1
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at Main$.create(f.scala:12)
at Main$.main(f.scala:14)
at Main.main(f.scala)
Scala 2.12.3
There's a number of changes that make the error go away. But making it non-anonymous makes it a compile error:
class BippyBar[A] extends Bar[Bippy[A]] {
def m(x: Bippy[A]) = 0
}error: bridge generated for member method m: (x: Bippy[A])Int in class BippyBar
which overrides method m: (x: A)Int in trait Bar
clashes with definition of the member itself;
both have erased type (x: Object)Int
def m(x: Bippy[A]) = 0
^
one error found