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Short version: we sometimes need to rewrite this as
new T(qual.asInstanceOf[OwnerOfFoo].foo)
Long version:
`adaptMember` in Erasure performs a few tasks, among them:
1. adding an empty argument list to qualifiers in `new qual.T`
for which `qual` is a val template member that has
(post uncurry) a MethodType with an empty parameter list.
The same rewriting was already applied in uncurry for such
qualifiers appearing in other contexts, e.g. `qual.foo` was
already rewritten to `qual().foo`.
2. casting, if necessary, the qualifier in `Select(qual, name)`
to the type of owner of the symbol that this selection
references.
This can be neccesary with compound types:
- some val class member has type `A with B`;
- we instantiate `new ab.valMemberOfB.T`
- we must pass `ab.valMemberOfB` to the constructor of `T`
as the `$outer` pointer
- we must cast `ab` to `B` before calling `valMemberOfB`.
Failure to insert this cast can lead to a LinkageError or
a VerifyError.
However, if 1) was performed, 2) was not.
The error is pretty easy to trigger with the new reflection
API:
class Test {
val cm: reflect.runtime.universe.Mirror
= reflect.runtime.currentMirror
def error {
new cm.universe.Traverser // java.lang.VerifyError
}
def okay1 {
val cm: reflect.runtime.universe.Mirror = reflect.runtime.currentMirror
new cm.universe.Traverser
}
}
The fix applied here to `adaptMember` mirrors the existing
implementation of `adaptType`.
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