return gen.New(gen.mkPrimaryConstr(pos, defs.TUPLE_CLASS[2], new Type[] { left.getType(), right.getType() }, new Tree[] { left, right }));
return gen.New(gen.mkApplyTV( gen.mkPrimaryConstructorGlobalRef( pos, defs.TUPLE_CLASS[2]), new Type[] { left.getType(), right.getType() }, new Tree[] { left, right }));
    Tree newPair( Tree left, Tree right ) { 	return gen.New(gen.mkPrimaryConstr(pos, defs.TUPLE_CLASS[2],			                   new Type[] { left.getType(), right.getType() },			                   new Tree[] { left, right }));    }    