Weird usage of Java Generics compiles correctly with JDT (and code runs) but does not compile with Oracle's Java6 compiler

[Maurizio Cimadamore]

Hi
These failures are caused by the fact that JDK 6 compiler doesn't 
implement type-inference correctly. A lot of effort has been put into 
JDK 7 compiler in order to get rid of all these problems (your program 
compiles fine in JDK 7). However, some of those inference improvements 
require source incompatible changes, which is why we cannot backport 
these fixes in the JDK 6 release.

Maurizio

On 21/02/12 12:43, Danilo Tommasina wrote:
> |class  MyWeirdClass  {
>
>      public  void  entryPoint()  {
>          doSomethingWeird();
>      }
>
>      @SuppressWarnings(  "unchecked"  )
>      private  <Textends  A&  B>  T getMyClass()  {
>          if  (  System.currentTimeMillis()  %  2  ==  0  )  {
>             return  (T)  new  MyClass_1();
>          }  else  {
>             return  (T)  new  MyClass_2();
>          }
>      }
>
>      private  <Textends  A&  B>  void  doSomethingWeird()  {
>          T obj=  getMyClass();
>
>          obj.methodFromA();
>          obj.methodFromB();
>      }
>
>      static  interface A{
>          void  methodFromA();
>      }
>
>      static  interface B{
>          void  methodFromB();
>      }
>
>      static  class  MyClass_1  implements  A,  B{
>          public  void  methodFromA()  {};
>          public  void  methodFromB()  {};
>      }
>
>      static  class  MyClass_2  implements  A,  B{
>          public  void  methodFromA()  {};
>          public  void  methodFromB()  {};
>      }
> }
> |

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