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/* VA.C: The program below illustrates passing a variable
* number of arguments using the following macros:
* va_start va_arg va_end
* va_list va_dcl (UNIX only)
*/
#include <stdio.h>
#include <stdarg.h>
int average( int first, ... );
union vararg_average {
int ints; /* We only pass ints to this one */
};
#include "testharness.h"
int main( void )
{
/* Call with 3 integers (-1 is used as terminator). */
if(average( 2, 3, 4, -1 ) != 3) E(1);
if(average( 5, 7, 9, 11, 13, -1 ) != 9) E(2);
if(average( -1 ) != 0) E(3);
SUCCESS;
}
/* Returns the average of a variable list of integers. */
int average( int first, ... )
{
int count = 0, sum = 0, i = first;
va_list marker;
va_start( marker, first ); /* Initialize variable arguments. */
while( i != -1 )
{
sum += i;
count++;
i = va_arg( marker, int);
}
va_end( marker ); /* Reset variable arguments. */
return( sum ? (sum / count) : 0 );
}
// Put this intentionally at the end
#pragma ccuredvararg("average", sizeof(union vararg_average))
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