ceph/src/boost/libs/safe_numerics/example/example6.cpp

   1 #include <stdexcept>
   2 #include <sstream>
   3 #include <iostream>
   4
   5 #include <boost/safe_numerics/safe_integer.hpp>
   6
   7 int main(int, const char *[]){
   8     // problem: checking of externally produced value can be overlooked
   9     std::cout << "example 6: ";
  10     std::cout << "checking of externally produced value can be overlooked" << std::endl;
  11     std::cout << "Not using safe numerics" << std::endl;
  12
  13     std::istringstream is("12317289372189 1231287389217389217893");
  14
  15     try{
  16         int x, y;
  17         is >> x >> y; // get integer values from the user
  18         std::cout << x << ' ' << y << std::endl;
  19         std::cout << "error NOT detected!" << std::endl;
  20     }
  21     catch(const std::exception &){
  22         std::cout << "error detected!" << std::endl;
  23     }
  24
  25     // solution: assign externally retrieved values to safe equivalents
  26     std::cout << "Using safe numerics" << std::endl;
  27     {
  28         using namespace boost::safe_numerics;
  29         safe<int> x, y;
  30         is.seekg(0);
  31         try{
  32             is >> x >> y; // get integer values from the user
  33             std::cout << x << ' ' << y << std::endl;
  34             std::cout << "error NOT detected!" << std::endl;
  35         }
  36         catch(const std::exception & e){
  37             std::cout << "error detected:"  << e.what() << std::endl;
  38         }
  39     }
  40     return 0;
  41 }