Return the offset of an element within a structure
#include <stddef.h> #define offsetof( composite, name ) …
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The offsetof() macro returns the offset of the element name within the struct or union composite.
This provides a portable method to determine the offset.
The offset of name.
#include <stdio.h> #include <stdlib.h> #include <stddef.h> struct new_def { char *first; char second[10]; int third; }; int main( void ) { printf( "first:%d second:%d third:%d\n", offsetof( struct new_def, first ), offsetof( struct new_def, second ), offsetof( struct new_def, third ) ); return EXIT_SUCCESS; }
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | Yes |
Signal handler | Yes |
Thread | Yes |