Example of numerical issues with double values.

leaky_double.cpp

#include <iostream>

int main()
{
    double val1 = -10.0 + 0.4*14 + 0.4;
    double val2 = -10.0 + 0.4*15;
    
    std::cout << "val1 = " << val1 << "; val2 = " << val2 << std::endl;
    std::cout << (val1 == val2 ? "Equal" : "Not equal") << std::endl;
    std::cout << (val1 == -4.0 ? "val1 is -4" : "val1 is not -4") << std::endl;
    std::cout << (val2 == -4.0 ? "val2 is -4" : "val2 is not -4") << std::endl;
    return 0;
}