Name: rmT116609 Date: 05/13/2004


FULL PRODUCT VERSION :
java version "1.4.2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-b28)
Java HotSpot(TM) Client VM (build 1.4.2-b28, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
The tertiary operator has a drawback.
The problem is that it cannot identify that two objects b & c are from the same base class, without requiring an explicit cast

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Consider an abstract base class A
Two derived classes B & C
Also a method set(A object) which accepts an object of type A


B b = new B();
C c = new C();
boolean isValid = false;

set(isValid ? b : c); //this does not work

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
set(isValid ? b : c); should work without cast
ACTUAL -
set(isValid ? b : c); requires cast

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Incompatible types; found C required B

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class Test {
    public static void main(String args[]) {
B b = new B();
C c = new C();
boolean isValid = false;

set(isValid ? b : c);
    }
    
    public static void set(A obj) {}
}

abstract class A {}

class B extends A{}

class C extends A{}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Cast either b or c to A as follows:

set(isValid ? (A) b : c);

OR

set(isValid ? b : (A) c);
(Incident Review ID: 242826)
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