How to return nothing from an integer function in C++?

August 15, 2022

Consider the following code:

#include <iostream>
int test(int a){
    if (a > 10){
        return a;
    }
    else{
        std::cout << "Error!";
        return nothing;
    }
}
int main(){
    std::cout << test(9);
    return 0;
}

What I want is that The integer function test(int a), return a if a > 10, otherwise return Error!. but since this is an integer function, it must return an integer value, but I want that it print Error and return nothing. Is there a way for do this? (Also note that I don’t want to use a void function)

>Solution :

#include <stdexcept>

int test(int a){
    if (a > 10){
        return a;
    }
        else{
            throw std::invalid_argument( "a is smaller or eq than 10" );
    
        }

}