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/commit.go b/commit.go
index cfc6a63..0869ef2 100644
--- a/commit.go
+++ b/commit.go
@@ -22,6 +22,7 @@ const (
 
 // Commit
 type Commit struct {
+	doNotCompare
 	Object
 	cast_ptr *C.git_commit
 }