diff --git a/src/array.h b/src/array.h
new file mode 100644
index 000000000..aadd021f1
--- /dev/null
+++ b/src/array.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_array_h__
+#define INCLUDE_array_h__
+
+#include "util.h"
+
+#define git_array_t(type) struct { type *ptr; size_t size, asize; }
+
+#define git_array_init(a) \
+	do { (a).size = (a).asize = 0; (a).ptr = NULL; } while (0)
+
+#define git_array_clear(a) \
+	do { git__free((a).ptr); git_array_init(a); } while (0)
+
+#define git_array_grow(a) do { \
+	void *new_array; size_t new_size = \
+	((a).asize >= 256) ? (a).asize + 256 : ((a).asize >= 8) ? (a).asize * 2 : 8; \
+	new_array = git__realloc((a).ptr, new_size * sizeof(*(a).ptr)); \
+	if (!new_array) { git_array_clear(a); } \
+	else { (a).ptr = new_array; (a).asize = new_size; } \
+	} while (0)
+
+#define GITERR_CHECK_ARRAY(a) GITERR_CHECK_ALLOC((a).ptr)
+
+#define git_array_alloc(a, el) do { \
+	if ((a).size >= (a).asize) git_array_grow(a); \
+	(el) = (a).ptr ? &(a).ptr[(a).size++] : NULL; \
+	} while (0)
+
+#define git_array_last(a) ((a).size ? &(a).ptr[(a).size - 1] : NULL)
+
+#define git_array_get(a, i) (((i) < (a).size) ? &(a).ptr[(i)] : NULL)
+
+#define git_array_size(a) (a).size
+
+#endif
diff --git a/src/diff_driver.h b/src/diff_driver.h
index b9881a7ed..af9fa073e 100644
--- a/src/diff_driver.h
+++ b/src/diff_driver.h
@@ -11,7 +11,7 @@
 
 typedef struct git_diff_driver_registry git_diff_driver_registry;
 
-git_diff_driver_registry *git_diff_driver_registry_new();
+git_diff_driver_registry *git_diff_driver_registry_new(void);
 void git_diff_driver_registry_free(git_diff_driver_registry *);
 
 typedef struct git_diff_driver git_diff_driver;