How integers are converted to boolean type

Anything other than 0 is coverted to true

#include<iostream>
int main() {
        bool b1,b2,b3,b4,b5,b6;
        b1 = -1;
        b2 = 1;
        b3 = 0;
        b4 = 244;
        b5 = true;
        b6 = false;
        std::cout << "b1 : " << b1 << "\n";
        std::cout << "b2 : " << b2 << "\n";
        std::cout << "b3 : " << b3 << "\n";
        std::cout << "b4 : " << b4 << "\n";
        std::cout << "b5 : " << b5 << "\n";
        std::cout << "b6 : " << b6 << "\n";
        return 0;
}

Output

$ ./a.out
b1 : 1
b2 : 1
b3 : 0
b4 : 1
b5 : 1
b6 : 0
$