// Compile: cc -std=c23 test_7_17_stdatomic.c
#include <stdatomic.h>
#include <assert.h>

int main(void){
  atomic_int x;// = ATOMIC_VAR_INIT(0);
  atomic_init(&x, 0);
  int old = atomic_fetch_add_explicit(&x, 2, memory_order_seq_cst);
  assert(old == 0 && atomic_load(&x) == 2);
  return 0;
}