safe_numerics/example/example14.cpp
Robert Ramey a06d9f7a69 added constexpr tests to checked result operations
added tests for check result < and == operations
correct implementation of some checked result types
added constexpr example
2018-12-10 14:12:47 -08:00

38 lines
1.2 KiB
C++

#include <stdexcept>
#include <iostream>
#include <boost/safe_numerics/safe_integer.hpp>
int main(int, const char *[]){
// problem: cannot recover from arithmetic errors
std::cout << "example 8: ";
std::cout << "cannot detect compile time arithmetic errors" << std::endl;
std::cout << "Not using safe numerics" << std::endl;
try{
const int x = 1;
const int y = 0;
// will emit warning at compile time
// will leave an invalid result at runtime.
std::cout << x / y; // will display "0"!
std::cout << "error NOT detected!" << std::endl;
}
catch(const std::exception &){
std::cout << "error detected!" << std::endl;
}
// solution: replace int with safe<int>
std::cout << "Using safe numerics" << std::endl;
try{
using namespace boost::safe_numerics;
const safe<int> x = 1;
const safe<int> y = 0;
// constexpr const safe<int> z = x / y; // note constexpr here!
std::cout << x / y; // error would be detected at runtime
std::cout << " error NOT detected!" << std::endl;
}
catch(const std::exception & e){
std::cout << "error detected:" << e.what() << std::endl;
}
return 0;
}