🚀 go-pugleaf

In article <4j06iu$7qm@solutions.solon.com>,
Antony Pace (UK/CH) <100576.1776@compuserve.com> wrote:
 >I am having problems writing a macro (Ansi C) for which I feel there
 >must be standard technique.  Can anyone help?
 >
 >Here is my first attempt at the macro.  I have defined an error type
 >which is a small structure with 3 variables in it.  I want to use a
 >macro to clear all the variables so that if the number or type of
 >variables change, only my macro has to change.
 >
 >typedef struct {
 >  int a;
 >  int b;
 >  int c;
 >} t_error;
 >
 >#define CLEAR_ERROR(e) { \
 >  (e).a = 0;             \
 >  (e).b = 0;             \
 >  (e).c = 0;             \
 >  TRACE("clear error");  \
 >}

what about: 
#define CLEAR_ERROR(e) \
  ( (e).a = (e).b = (e).c = 0, TRACE( "clear error" ) )
where TRACE(s) is:
  #define TRACE(s)  ( traceon ? fprintf( ... ) : 0 )