C++ function that returns multiple types and multiple types as argument

cpp_multiple_types.cpp

#include <iostream>


template <typename T>
T perform_operation(const T& left, std::string op, const T& right) {
    if (op == "+")
        return left + right;
    if (op == "-")
        return left - right;
}

std::string perform_operation(std::string left, std::string op, std::string right) {
    if (op == "+")
        return left + right;

    return "";
}

int perform_operation(int left, std::string op, int right) {
    if (op == "+")
        return left + right;
    if (op == "-")
        return left - right;

    return 0;
}

float perform_operation(float left, std::string op, float right) {
    if (op == "+")
        return left + right;
    if (op == "-")
        return left - right;

    return 0;
}

int main(int argc, char** argv) {
    // supports strings
    std::cout << perform_operation("hello", "+", " world") << std::endl;

    // supports integers
    std::cout << perform_operation(1, "+", 1) << std::endl;
    std::cout << perform_operation(1, "-", 1) << std::endl;

    // supports floats
    std::cout << perform_operation(10.56, "-", 32.5) << std::endl;

    return 0;
};