Use #pragma once instead of #ifndef
Only the public header maintains #ifndef in the header, together with
pragma. The other ones contain only pragma.
As reported by Shawn Landden on systemd mailing list this is compatible
with all major compilers and gcc has this since version 3.3.
diff --git a/libkmod/libkmod-hash.h b/libkmod/libkmod-hash.h
index 8f20b8f..ca0af05 100644
--- a/libkmod/libkmod-hash.h
+++ b/libkmod/libkmod-hash.h
@@ -1,5 +1,4 @@
-#ifndef _LIBKMOD_HASH_H_
-#define _LIBKMOD_HASH_H_
+#pragma once
#include <stdbool.h>
@@ -21,5 +20,3 @@
void hash_iter_init(const struct hash *hash, struct hash_iter *iter);
bool hash_iter_next(struct hash_iter *iter, const char **key,
const void **value);
-
-#endif