`sig
type src
type dst
val blit :
(Blit_intf.S_distinct.src, Blit_intf.S_distinct.dst) Blit_intf.blit
val blito :
(Blit_intf.S_distinct.src, Blit_intf.S_distinct.dst) Blit_intf.blito
val unsafe_blit :
(Blit_intf.S_distinct.src, Blit_intf.S_distinct.dst) Blit_intf.blit
val sub :
(Blit_intf.S_distinct.src, Blit_intf.S_distinct.dst) Blit_intf.sub
val subo :
(Blit_intf.S_distinct.src, Blit_intf.S_distinct.dst) Blit_intf.subo
end`