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The code below produces an error at the function call of m in class C. "The method m(String) is ambiguous for the type B" javac from jdk1.5.0_03 compiles the code without warnings. Removing the "extends A" from class B removes the problem. Removing the "extends Comparable<T>" from A and B removes the problem. I have been unable to find a formal description of the java generics but I can't see how method m can be considered ambiguous. ----------------------------Start of test\C.java------------------------------ package test; abstract class A { abstract <T extends Comparable<T>> void m(T x); } class B extends A { <T extends Comparable<T>> void m(T x) { } } public class C { public static void main(String[] args) { new B().m(""); } } --------------------End of test\C.java-------------------------- Results from eclipse Problems window: Severity 2 Description The method m(String) is ambiguous for the type B Resource C.java In Folder TestT/test Location line 19
Need to change TypeVariableBinding.isInterchangeableWith() to: for (int i = 0; i < length; i++) { if (this.superInterfaces[i] != otherVariable.superInterfaces[i]) { if (this.superInterfaces[i].erasure() != otherVariable.superInterfaces [i].erasure()) return false; // no way it can match after substitution break identical; } } identical: { if (this.superclass != otherVariable.superclass) { if (this.superclass.erasure() != otherVariable.superclass.erasure()) return false; // no way it can match after substitution break identical; } for (int i = 0; i < length; i++) { if (this.superInterfaces[i] != otherVariable.superInterfaces[i]) { if (this.superInterfaces[i].erasure() ! = otherVariable.superInterfaces[i].erasure()) return false; // no way it can match after substitution break identical; } } return true; } // need substitutions Substitution subst = new Substitution() { public LookupEnvironment environment() { return environment; } public boolean isRawSubstitution() { return false; } public TypeBinding substitute(TypeVariableBinding typeVariable) { return typeVariable == otherVariable ? TypeVariableBinding.this : typeVariable; } }; if (this.superclass != Scope.substitute(subst, otherVariable.superclass)) return false; for (int i = 0; i < length; i++) if (this.superInterfaces[i] != Scope.substitute(subst, otherVariable.superInterfaces[i])) return false; return true; }
That should have read... Need to change TypeVariableBinding.isInterchangeableWith() to: for (int i = 0; i < length; i++) { if (this.superInterfaces[i] != otherVariable.superInterfaces[i]) { if (this.superInterfaces[i].erasure() != otherVariable.superInterfaces [i].erasure()) return false; // no way it can match after substitution break identical; } }
The following code also cannot be compiled by RC3: public class Bug { public static interface Interface1<E> { public void method(E object); } public static interface Interface2<E> { public void method(E obj); } public static interface Interface3<E> extends Interface1<E>, Interface2<E> { } public static class Class1 implements Interface3<String> { public void method(String o) { System.out.println(o); } } public static void main(String[] args) { Interface3<String> object1 = new Class1(); // Eclipse thinks this call is ambiguous object1.method("Hello world"); } }
Is there an ETA on this fix? It turns out to be a critical blocker for us as after a huge 3 week generics refactoring operation we can't get our code to compile now because of this error. Perhaps it'll make it into tonight's build? :)
We do not have a fix for it yet. I would guess a couple weeks unless extra incentive is emailed to an offshore account. ;) Seriously - its on top of the list so cross your fingers.
That's great - in the meantime folk might want to know that the problem isn't exhibited in 3.1M7, so we've regressed back to that milestone release for now.
*** Bug 105645 has been marked as a duplicate of this bug. ***
Philippe, this one will be fixed when the tiebreak method for: <T extends Comparable<T>> void m(T x) is void m(Comparable<String> x) instead of void m(Comparable<T> x) We also need to make sure the tieBreak method for: <T> void m(Comparable<String> x) is void m(Comparable<String> x) instead of void m(Comparable#RAW x)
Fix will not be ready for 3.1.1, removing target milestone "3.1.1"
Please can you fix this. I make heavy use of a class/interface OrderedSet<E> that extends the std Java List<E> and Set<E> classes. This bug means that all the code is uncompilable due to the 'method X is ambiguous' error. I'm currently using version 3.1.0 and would really like to use the later versions, but can't due to this bug.
I've tried the 2 cases described in this PR (with the latest 3.2 intergration build) and recent changes in the last few months have fixed these cases. Please open new PRs for any other cases which are still failing. Added AmbiguousMethodTest test1 and test2 for these cases.
Verified for 3.2 M5 using build I20060214-0010
