root/include/linux/typecheck.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef TYPECHECK_H_INCLUDED
#define TYPECHECK_H_INCLUDED

/*
 * Check at compile time that something is of a particular type.
 * Always evaluates to 1 so you may use it easily in comparisons.
 */
#define typecheck(type,x) \
({      type __dummy; \
        typeof(x) __dummy2; \
        (void)(&__dummy == &__dummy2); \
        1; \
})

/*
 * Check at compile time that 'function' is a certain type, or is a pointer
 * to that type (needs to use typedef for the function type.)
 */
#define typecheck_fn(type,function) \
({      typeof(type) __tmp = function; \
        (void)__tmp; \
})

/*
 * Check at compile time that something is a pointer type.
 */
#define typecheck_pointer(x) \
({      typeof(x) __dummy; \
        (void)sizeof(*__dummy); \
        1; \
})

#endif          /* TYPECHECK_H_INCLUDED */