ceph/src/boost/libs/safe_numerics/example/example13.cpp

   1 #include <stdexcept>
   2 #include <iostream>
   3
   4 #include <boost/safe_numerics/safe_integer.hpp>
   5
   6 int main(int, const char *[]){
   7     // problem: cannot recover from arithmetic errors
   8     std::cout << "example 7: ";
   9     std::cout << "cannot recover from arithmetic errors" << std::endl;
  10     std::cout << "Not using safe numerics" << std::endl;
  11
  12     try{
  13         int x = 1;
  14         int y = 0;
  15         // can't do this as it will crash the program with no
  16         // opportunity for recovery - comment out for example
  17         // std::cout << x / y;
  18         std::cout << "error cannot be handled at runtime!" << std::endl;
  19     }
  20     catch(const std::exception &){
  21         std::cout << "error handled at runtime!" << std::endl;
  22     }
  23     // solution: replace int with safe<int>
  24     std::cout << "Using safe numerics" << std::endl;
  25     try{
  26         using namespace boost::safe_numerics;
  27         const safe<int> x = 1;
  28         const safe<int> y = 0;
  29         std::cout << x / y;
  30         std::cout << "error NOT detected!" << std::endl;
  31     }
  32     catch(const std::exception & e){
  33         std::cout << "error handled at runtime!" << e.what() << std::endl;
  34     }
  35     return 0;
  36 }