1 // struct ABC is expensive to copy and should be
2 // passed as a const reference.
3 struct ABC {
4   ABC(const ABC&);
5   int get(int) const;
6 };
7 
8 
9 int f1(int n,              const ABC& v1,   const ABC& v2); // line 9
10 
11 int f1(int n, ABC v1); // line 11
12 
13 
14 
15 int f2(        int n,       const ABC& v2); // line 15
16