Enable operator-sensitive extension of element-type promotion#12292

Merged

timholy merged 3 commits intomasterfrom teh/promotion

Jul 29, 2015

+153-31

Commits on Jul 29, 2015

Add promote_op, which uses inference to determine types (fixes #8027 )
timholy
committed
Don't use inference in promote_op, just fall back to promote_type.
timholy
committed
Switch promote_op implementations to static Functors
timholy
committed