Duplicate :
|
FULL PRODUCT VERSION : java version "1.6.0_20" OpenJDK Runtime Environment (IcedTea6 1.9.1) (6b20-1.9.1-1ubuntu3) OpenJDK 64-Bit Server VM (build 17.0-b16, mixed mode) ADDITIONAL OS VERSION INFORMATION : Linux notebook 2.6.35-22-generic #35-Ubuntu SMP Sat Oct 16 20:45:36 UTC 2010 x86_64 GNU/Linux A DESCRIPTION OF THE PROBLEM : a certain boolean expression involving generics (see code below) is deemed illegal when used inside of an assertion. When the expression is stored in a boolean variable instead, no error occurs. STEPS TO FOLLOW TO REPRODUCE THE PROBLEM : Apply javac to the class given below. $ javac AClass.java EXPECTED VERSUS ACTUAL BEHAVIOR : EXPECTED - a clean compile. ACTUAL - a compilation error ERROR MESSAGES/STACK TRACES THAT OCCUR : AClass.java:18: illegal start of expression assert(AClass.<Integer> mk().isX()); ^ 1 error REPRODUCIBILITY : This bug can be reproduced always. ---------- BEGIN SOURCE ---------- public abstract class AClass<N> { public abstract boolean isX(); public static <K> AClass<K> mk() { return new AClass<K> () { @Override public boolean isX() { return true; } }; } public static void test() { assert(AClass.<Integer> mk().isX()); } } ---------- END SOURCE ---------- CUSTOMER SUBMITTED WORKAROUND : public abstract class AClass<N> { public abstract boolean isX(); public static <K> AClass<K> mk() { return new AClass<K> () { @Override public boolean isX() { return true; } }; } public static void test() { boolean x = AClass.<Integer> mk().isX(); assert x; } }