offsetof
offsetof
Defined in header <stddef.h> | ||
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#define offsetof(type, member) /*implementation-defined*/ |
The macro offsetof
expands to a constant of type size_t
, the value of which is the offset, in bytes, from the beginning of an object of specified type to its specified member, including padding if any.
Example
#include <stdio.h> #include <stddef.h> struct S { char c; double d; }; int main(void) { printf("the first element is at offset %zu\n", offsetof(struct S, c)); pr