/* CC0 (Public domain) - see LICENSE file for details */ | |
#ifndef CCAN_ARRAY_SIZE_H | |
#define CCAN_ARRAY_SIZE_H | |
#include "config.h" | |
#include <ccan/build_assert/build_assert.h> | |
/** | |
* ARRAY_SIZE - get the number of elements in a visible array | |
* @arr: the array whose size you want. | |
* | |
* This does not work on pointers, or arrays declared as [], or | |
* function parameters. With correct compiler support, such usage | |
* will cause a build error (see build_assert). | |
*/ | |
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + _array_size_chk(arr)) | |
#if HAVE_BUILTIN_TYPES_COMPATIBLE_P && HAVE_TYPEOF | |
/* Two gcc extensions. | |
* &a[0] degrades to a pointer: a different type from an array */ | |
#define _array_size_chk(arr) \ | |
BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(typeof(arr), \ | |
typeof(&(arr)[0]))) | |
#else | |
#define _array_size_chk(arr) 0 | |
#endif | |
#endif /* CCAN_ALIGNOF_H */ |