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Diffstat (limited to 'include/array_length.h')
| -rw-r--r-- | include/array_length.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/array_length.h b/include/array_length.h new file mode 100644 index 0000000000..cb4a8b2a56 --- /dev/null +++ b/include/array_length.h @@ -0,0 +1,36 @@ +/* The array_length and array_end macros. + Copyright (C) 2017 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 + <http://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) \ + __extension__ ({ \ + _Static_assert (!__builtin_types_compatible_p \ + (__typeof (var), __typeof (&(var)[0])), \ + "argument must be an array"); \ + sizeof (var) / sizeof ((var)[0]); \ + }) + +/* 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)]) + +#endif /* _ARRAY_LENGTH_H */ |