Make all non-user-creatable structures non-comparable (#802)

This change makes all non-user-creatable structures non-comparable. This
makes it easier to add changes later that don't introduce breaking
changes from the go compatibility guarantees perspective.

This, of course, implies that this change _is_ a breaking change, but since
these structures are not intended to be created by users (or de-referenced),
it should be okay.

1 files changed, 1 insertions, 0 deletions

diff --git a/mempack.go b/mempack.go
index bdea224..14898f9 100644
--- a/mempack.go
+++ b/mempack.go
@@ -18,6 +18,7 @@ import (
 
 // Mempack is a custom ODB backend that permits packing object in-memory.
 type Mempack struct {
+	doNotCompare
 	ptr *C.git_odb_backend
 }