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author | Florian Weimer <fweimer@redhat.com> | 2017-11-02 12:14:01 +0100 |
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committer | Florian Weimer <fweimer@redhat.com> | 2017-11-02 12:45:20 +0100 |
commit | c94a5688fb1228a862b2d4a3f1239cdc0e3349e5 (patch) | |
tree | b427ab064d39977d8ffbb5363e78f767ad6492c4 /include | |
parent | 067f5d97b37216eb26ffe7bfdefd0da9b0425b68 (diff) | |
download | glibc-c94a5688fb1228a862b2d4a3f1239cdc0e3349e5.tar.gz glibc-c94a5688fb1228a862b2d4a3f1239cdc0e3349e5.tar.xz glibc-c94a5688fb1228a862b2d4a3f1239cdc0e3349e5.zip |
<array_length.h>: New array_length and array_end macros
Diffstat (limited to 'include')
-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 */ |