Understanding access restriction of variant parametric types and Java wildcards.

Giovanni Rimassa Mirko Viroli Understanding access restriction of variant parametric types and Java wildcards. 1390-1397 2005 conf/sac/2005 SAC http://doi.acm.org/10.1145/1066677.1066993 db/conf/sac/sac2005.html#RimassaV05