addition and subtraction of two numbers using operator overloading - c++

Question

#include<iostream>
using namespace std;
class add
{
private: int a,b;
public: add(int x=0)
{
a=x;
}
add operator+(add const &c) // sub operator-(sub const &c)
{ //{
add sum; // sub diff;
sum.a=a+c.a; // diff.a=a-c.a;
return sum; // return diff
} //}
void print()
{
cout<<"sum: "<<a;
}
};
int main()
{
add a1(10),a2(5); //sub s1(10),s2(5);
add a3=a1+a2; // sub s3=s1-s2;
a3.print(); // s3.print();
return 0;
}
Here I've written seperately but what to do if I need to do both in a single code?
I want a C++ code to perform them simultaneously

Answer 1

You can define any reasonable combination of:
Foo operator+(arg);
Foo operator-(arg);
Foo operator*(arg);
Foo operator/(arg);
And the arg can be another Foo or some other type entirely. For instance:
#include <iostream>
using namespace std;
class Operators {
public:
Operators() = default;
Operators(int v) : value(v) {}
Operators operator+(const Operators &other) {
return Operators{value + other.value};
}
Operators operator+(const int byValue) {
return Operators{value + byValue};
}
Operators operator-(const Operators &other) {
return Operators{value - other.value};
}
Operators operator-(const int byValue) {
return Operators{value - byValue};
}
Operators operator*(const Operators &other) {
return Operators{value * other.value};
}
Operators operator/(const Operators &other) {
return Operators{value / other.value};
}
int value = 0;
};
int main(int, char **) {
Operators first{10};
Operators second{20};
Operators result1 = first + second;
Operators result2 = first * second;
Operators result3 = first * 3;
Operators result4 = second / 2;
cout << "first + second == " << result1.value << endl;
cout << "first * second == " << result2.value << endl;
cout << "first * 3 == " << result3.value << endl;
cout << "first / 2 == " << result4.value << endl;
}
first + second == 30
first * second == 200
first * 3 == 30
first / 2 == 10
You'll see I overwrote operators that take two Operators objects, but I also wrote a few that take an integer argument, too.
I compiled and ran that with:
g++ --std=c++17 Whatever.cpp -o Whatever && Whatever