feat allocator: added malloc zalloc class templates examples

Signed-off-by: John Sanpe <sanpeqf@gmail.com>

Author: pixclk

examples/allocator/guards.c

@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright(c) 2025 John Sanpe <sanpeqf@gmail.com>
+ */
+
+#include <string.h>
+#include <bfdev/allocator.h>
+#include <bfdev/size.h>
+
+#define TEST_SIZE BFDEV_SZ_64KiB
+
+static int
+test_cleanup(void)
+{
+    BFDEV_CLEAN(bfdev_free) void *ptr;
+
+    ptr = bfdev_malloc(NULL, TEST_SIZE);
+    if (!ptr)
+        return 1;
+    bzero(ptr, TEST_SIZE);
+
+    return 0;
+}
+
+static int
+test_class_malloc(void)
+{
+    BFDEV_CLASS(bfdev_malloc, ptr)(TEST_SIZE);
+
+    if (!ptr)
+        return 1;
+    bzero(ptr, TEST_SIZE);
+
+    return 0;
+}
+
+static int
+test_class_zalloc(void)
+{
+    BFDEV_CLASS(bfdev_zalloc, ptr)(TEST_SIZE);
+
+    if (!ptr)
+        return 1;
+    bzero(ptr, TEST_SIZE);
+
+    return 0;
+}
+
+int
+main(int argc, char const *argv[])
+{
+    int retval;
+
+    if ((retval = test_cleanup()) ||
+        (retval = test_class_malloc()) ||
+        (retval = test_class_zalloc()))
+        return retval;
+
+    return 0;
+}