Work-around GCC polymorphism problems.
Work-around GCC polymorphism problems.

Change-Id: Ica1d8e6840cdd9ba493405e66c1728b5da9540a2

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst