C++ How to Program, 10/e

... functions
 6   // upon detecting division-by-zero exceptions
 7   class DivideByZeroException :  public std::runtime_error {
 8   public:
 9   // constructor specifies default error message
10    DivideByZeroException()
11       : std::runtime_error{"attempted to divide by zero"} {}
12   };

17.2.2 Demonstrating Exception Handling

Figure 17.2 uses exception handling to wrap code that might throw a DivideByZeroException and to handle that exception, should one occur. The user enters two integers, which are passed as arguments to function quotient (lines 10–18). This function divides its first parameter (numerator) by its second parameter (denominator). Assuming that the user does not specify 0 as the denominator for the division, function quotient returns the division result. ...