OFFSETOF(3) | Library Functions Manual | OFFSETOF(3)

# NAME

`offsetof` — offset of a structure member

# SYNOPSIS

`#include <stddef.h>`

size_t
`offsetof`(type, member);

# DESCRIPTION

The `offsetof`() macro expands to an integer constant expression of type size_t and yields the offset, in bytes, of the field member from the start of the structure type.

A compiler error will result if member is not aligned to a byte boundary (i.e. it is a bit-field).

# STANDARDS

The `offsetof`() macro conforms to ANSI X3.159-1989 (“ANSI C89”).

June 5, 2013 | Debian