PracticeDev/study_cpp/cpp_primer_source_code/Chapter 14/manyfrnd.cpp

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2022-12-20 17:31:11 +08:00
// manyfrnd.cpp -- unbound template friend to a template class
#include <iostream>
using std::cout;
using std::endl;
template <typename T>
class ManyFriend
{
private:
T item;
public:
ManyFriend(const T & i) : item(i) {}
template <typename C, typename D> friend void show2(C &, D &);
};
template <typename C, typename D> void show2(C & c, D & d)
{
cout << c.item << ", " << d.item << endl;
}
int main()
{
ManyFriend<int> hfi1(10);
ManyFriend<int> hfi2(20);
ManyFriend<double> hfdb(10.5);
cout << "hfi1, hfi2: ";
show2(hfi1, hfi2);
cout << "hfdb, hfi2: ";
show2(hfdb, hfi2);
// std::cin.get();
return 0;
}