53 lines
1.6 KiB
C++
53 lines
1.6 KiB
C++
// 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 <iostream>
|
|
#include <limits>
|
|
|
|
#include <boost/rational.hpp>
|
|
#include <boost/safe_numerics/safe_integer.hpp>
|
|
|
|
int main(int, const char *[]){
|
|
// simple demo of rational library
|
|
const boost::rational<int> r {1, 2};
|
|
std::cout << "r = " << r << std::endl;
|
|
const boost::rational<int> q {-2, 4};
|
|
std::cout << "q = " << q << std::endl;
|
|
// display the product
|
|
std::cout << "r * q = " << r * q << std::endl;
|
|
|
|
// problem: rational doesn't handle integer overflow well
|
|
const boost::rational<int> c {1, INT_MAX};
|
|
std::cout << "c = " << c << std::endl;
|
|
const boost::rational<int> d {1, 2};
|
|
std::cout << "d = " << d << std::endl;
|
|
// display the product - wrong answer
|
|
std::cout << "c * d = " << c * d << std::endl;
|
|
|
|
// solution: use safe integer in rational definition
|
|
using safe_rational = boost::rational<
|
|
boost::safe_numerics::safe<int>
|
|
>;
|
|
|
|
// use rationals created with safe_t
|
|
const safe_rational sc {1, std::numeric_limits<int>::max()};
|
|
|
|
std::cout << "c = " << sc << std::endl;
|
|
const safe_rational sd {1, 2};
|
|
std::cout << "d = " << sd << std::endl;
|
|
std::cout << "c * d = ";
|
|
try {
|
|
// multiply them. This will overflow
|
|
std::cout << (sc * sd) << std::endl;
|
|
}
|
|
catch (std::exception const& e) {
|
|
// catch exception due to multiplication overflow
|
|
std::cout << e.what() << std::endl;
|
|
}
|
|
|
|
return 0;
|
|
}
|