void link_error();
struct OOf {
int value;
OOf() {value = 0;}
};
inline OOf operator+(OOf op1, OOf op2)
{
OOf f;
f.value = op1.value + op2.value;
return f;
}
inline OOf operator*(OOf op1, OOf op2)
{
OOf f;
f.value = op1.value * op2.value;
return f;
}
inline OOf operator-(OOf op1, OOf op2)
{
OOf f;
f.value = op1.value - op2.value;
return f;
}
inline OOf test_func(
OOf a,
OOf b,
OOf c
)
{
OOf d, e;
OOf result;
d = a * b + b * c;
e = a * c - b * d;
result = d * e;
return result;
}
void test()
{
OOf a, b, c;
OOf d = test_func (a,b,c);
if (d.value)
link_error();
}