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/* SPDX-License-Identifier: MIT */
/**
* utils.h - useful macros for compile-time magic
*
* Inspired by similar macros in the Linux Kernel.
*
* Copyright (c) 2023 - Yaroslav de la Peña Smirnov
*/
#ifndef CWARE_UTILS_H
#define CWARE_UTILS_H
#include <stddef.h>
#ifndef static_assert
#define static_assert(exp, msg) _Static_assert(exp, msg)
#endif
#define same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#define container_of(ptr, T, member) \
({ \
static_assert(same_type(*(ptr), ((T *)0)->member) \
|| same_type(*(ptr), void), \
"type mismatch in container_of()"); \
(T *)((void *)(ptr)-offsetof(T, member)); \
})
#define ARRAY_SIZE(arr) \
({ \
static_assert(!same_type((arr), &(arr)[0]), \
"variable is not an array"); \
sizeof(arr) / sizeof(*arr); \
})
#endif
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