INTEGER*1 X
X = -5
CALL CENTRY(X)
PRINT *,
1  'UPDATED VALUE IN FORTRAN:', X
END

extern "FORTRAN"
{ void centry(signed char &); }
#include <stdio.h>
void centry(signed char &x)
{
  printf("C char arg value: %d\n",x);
  x -= 1;
}