glibc/include/array_length.h

51 lines
2.2 KiB
C

/* The array_length and array_end macros.
Copyright (C) 2017-2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _ARRAY_LENGTH_H
#define _ARRAY_LENGTH_H
/* array_length (VAR) is the number of elements in the array VAR. VAR
must evaluate to an array, not a pointer. */
#define array_length(var) \
(sizeof (var) / sizeof ((var)[0]) \
+ 0 * sizeof (struct { \
_Static_assert (!__builtin_types_compatible_p \
(__typeof (var), __typeof (&(var)[0])), \
"argument must be an array"); \
}))
/* array_end (VAR) is a pointer one past the end of the array VAR.
VAR must evaluate to an array, not a pointer. */
#define array_end(var) (&(var)[array_length (var)])
/* array_foreach (PTR, ARRAY) iterates over all the elements in an
array, assigning the locally defined pointer variable PTR to each
element in turn.
array_foreach_const (PTR, ARRAY) does the same, but *PTR is declared
const even if the array is not. */
#define array_foreach(ptr, array) \
for (__typeof ((array)[0]) *ptr = (array) ; \
ptr < array_end (array) ; ptr++)
#define array_foreach_const(ptr, array) \
for (const __typeof ((array)[0]) *ptr = (array) ; \
ptr < array_end (array) ; ptr++)
#endif /* _ARRAY_LENGTH_H */