conversion operator in C++

Conversion operators convert one concrete type to another concrete type or primitive type implicitly. It is similar to the operator overloading function in class.
```
#include <iostream>
using namespace std;

struct S {
    float num;
};

class C {
private:
    int num;
public:
    C(int n) { num = n; }
 
    operator S() const {
        S s;
        s.num=num*1.1;
        return s;
    }
};
 
int main() {
    C c(2);
    S s(c);
    cout << s.num << endl;
}
```