Libc-1272.200.26.tar.gz

[apple/libc.git] / include / struct.h

diff --git a/include/struct.h b/include/struct.h
index f80ecd0771324cb396c6ff98ddb8304a28c09bbb..e8dab2c2a26957ea342a283f365fdbedc39a196a 100644 (file)
--- a/include/struct.h
+++ b/include/struct.h
@@ -48,4 +48,21 @@
 #define        strbase(name, addr, field) \
        ((struct name *)((char *)(addr) - fldoff(name, field)))
 
+/* Number of elements in a statically-defined array */
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L && __GNUC__
+#define countof(arr) ({ \
+       _Static_assert( \
+                       !__builtin_types_compatible_p(typeof(arr), typeof(&(arr)[0])), \
+                       "array must be statically defined"); \
+       (sizeof(arr) / sizeof(arr[0])); \
+})
+#else
+#define countof(arr) \
+       (sizeof(arr) / sizeof(arr[0]))
+#endif
+
+/* Length of a statically-defined string (does not include null terminator) */
+#define lenof(str) \
+       (sizeof(str) - 1)
+
 #endif /* !_STRUCT_H_ */