// Copyright (c) 2018 Robert Ramey // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #include #include int main(int, const char *[]){ std::cout << "example 2:"; std::cout << "undetected overflow in data type" << std::endl; // problem: undetected overflow std::cout << "Not using safe numerics" << std::endl; try{ int x = INT_MAX; // the following silently produces an incorrect result ++x; std::cout << x << " != " << INT_MAX << " + 1" << std::endl; std::cout << "error NOT detected!" << std::endl; } catch(const std::exception &){ std::cout << "error detected!" << std::endl; } // solution: replace int with safe std::cout << "Using safe numerics" << std::endl; try{ using namespace boost::safe_numerics; safe x = INT_MAX; // throws exception when result is past maximum possible ++x; assert(false); // never arrive here } catch(const std::exception & e){ std::cout << e.what() << std::endl; std::cout << "error detected!" << std::endl; } return 0; }