Retrieves the offset of a member from the beginning of its parent structure.
size_t offsetof(
structName,
memberName
);
Parameters
- structName
-
Name of the parent data structure.
- memberName
-
Name of the member in the parent data structure for which to determine the offset.
offsetof returns the offset in bytes of the specified member from the beginning of its parent data structure. It is undefined for bit fields.
The offsetof macro returns the offset in bytes of memberName from the beginning of the structure specified by structName. You can specify types with the struct keyword.
Note |
|---|
| offsetof is not a function and cannot be described using a C prototype. |
|
Routine
|
Required header
|
Compatibility
|
| offsetof | <stddef.h> |
ANSI, Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition, Windows Millennium Edition, Windows NT 4.0, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
Reference
Memory Allocation