nostrdb

an unfairly fast embedded nostr database backed by lmdb
git clone git://jb55.com/nostrdb
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array_size.h (919B)


      1 /* CC0 (Public domain) - see LICENSE file for details */
      2 #ifndef CCAN_ARRAY_SIZE_H
      3 #define CCAN_ARRAY_SIZE_H
      4 #include "../config.h"
      5 #include "build_assert.h"
      6 
      7 /**
      8  * ARRAY_SIZE - get the number of elements in a visible array
      9  * @arr: the array whose size you want.
     10  *
     11  * This does not work on pointers, or arrays declared as [], or
     12  * function parameters.  With correct compiler support, such usage
     13  * will cause a build error (see build_assert).
     14  */
     15 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + _array_size_chk(arr))
     16 
     17 #if HAVE_BUILTIN_TYPES_COMPATIBLE_P && HAVE_TYPEOF
     18 /* Two gcc extensions.
     19  * &a[0] degrades to a pointer: a different type from an array */
     20 #define _array_size_chk(arr)                        \
     21     BUILD_ASSERT_OR_ZERO(!__builtin_types_compatible_p(typeof(arr),    \
     22                             typeof(&(arr)[0])))
     23 #else
     24 #define _array_size_chk(arr) 0
     25 #endif
     26 #endif /* CCAN_ALIGNOF_H */