1 /* The array_length and array_end macros. 2 Copyright (C) 2017-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _ARRAY_LENGTH_H 20 #define _ARRAY_LENGTH_H 21 22 /* array_length (VAR) is the number of elements in the array VAR. VAR 23 must evaluate to an array, not a pointer. */ 24 #define array_length(var) \ 25 (sizeof (var) / sizeof ((var)[0]) \ 26 + 0 * sizeof (struct { \ 27 _Static_assert (!__builtin_types_compatible_p \ 28 (__typeof (var), __typeof (&(var)[0])), \ 29 "argument must be an array"); \ 30 })) 31 32 /* array_end (VAR) is a pointer one past the end of the array VAR. 33 VAR must evaluate to an array, not a pointer. */ 34 #define array_end(var) (&(var)[array_length (var)]) 35 36 #endif /* _ARRAY_LENGTH_H */ 37