// Function to check if a value is negative bool isError(double val) { if (val < 0) { return true; } else { return false; } } // Usage example double x = -1.5; if (isError(x)) { std::cout << "Error: value is negative" << std::endl; }
// Function to divide two numbers double divide(double num, double denom) { if (denom == 0) { std::cerr << "Error: division by zero" << std::endl; return NAN; // Not a number } else { return num / denom; } } // Usage example double x = 10; double y = 0; double result = divide(x, y); if (isError(result)) { std::cout << "Error: division by zero" << std::endl; }This code defines a custom function, divide, that performs division of two numbers. If the denominator is zero, indicating an error condition, it outputs an error message to the standard error stream and returns NAN. The usage example checks if the result of the division operation is an error by using the isError function. Without further information about what library or package isError belongs to, it is difficult to determine its functionality or use case.