| 1 | // Copyright (c) 2018 Robert Ramey |
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| 2 | // |
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| 3 | // Distributed under the Boost Software License, Version 1.0. (See |
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| 4 | // accompanying file LICENSE_1_0.txt or copy at |
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| 5 | // http://www.boost.org/LICENSE_1_0.txt) |
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| 6 | |
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| 7 | #include <stdexcept> |
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| 8 | #include <iostream> |
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| 9 | |
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| 10 | #include <boost/safe_numerics/safe_integer.hpp> |
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| 11 | |
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| 12 | int main(int, const char *[]){ |
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| 13 | // problem: cannot recover from arithmetic errors |
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| 14 | std::cout << "example 14: " ; |
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| 15 | std::cout << "cannot detect compile time arithmetic errors" << std::endl; |
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| 16 | std::cout << "Not using safe numerics" << std::endl; |
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| 17 | |
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| 18 | try{ |
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| 19 | const int x = 1; |
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| 20 | const int y = 0; |
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| 21 | // will emit warning at compile time |
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| 22 | // will leave an invalid result at runtime. |
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| 23 | std::cout << x / y; // will display "0"! |
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| 24 | std::cout << "error NOT detected!" << std::endl; |
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| 25 | } |
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| 26 | catch(const std::exception &){ |
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| 27 | std::cout << "error detected!" << std::endl; |
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| 28 | } |
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| 29 | // solution: replace int with safe<int> |
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| 30 | std::cout << "Using safe numerics" << std::endl; |
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| 31 | try{ |
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| 32 | using namespace boost::safe_numerics; |
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| 33 | const safe<int> x = 1; |
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| 34 | const safe<int> y = 0; |
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| 35 | // constexpr const safe<int> z = x / y; // note constexpr here! |
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| 36 | std::cout << x / y; // error would be detected at runtime |
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| 37 | std::cout << " error NOT detected!" << std::endl; |
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| 38 | } |
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| 39 | catch(const std::exception & e){ |
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| 40 | std::cout << "error detected:" << e.what() << std::endl; |
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| 41 | } |
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| 42 | return 0; |
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| 43 | } |
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| 44 | |
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