VistaIOOffset(3) determine the byte offset of a structure field

Other Alias

VistaIOOffsetOf

SYNTAX

#include <vistaio.h>

size_t VistaIOOffset (pointer_type, field_name)
Type pointer_type; Field field_name;
size_t VistaIOOffsetOf (struct_type, field_name)
Type struct_type; Field field_name;

ARGUMENTS

field_name
Specifies the name of a structure field for which to calculate the byte offset.
pointer_type
Specifies a type that is declared as a pointer to a structure.
struct_type
Specifies a type that is declared as a structure.

DESCRIPTION

The VistaIOOffset and VistaIOOffsetOf macros return the byte offset of the field_name field within its structure.

NOTES

These are equivalent to the X Toolkit macros XtOffset(3Xt) and XtOffsetOf(3Xt). ANSI C defines an offsetof macro, which is to be preferred over any of these.