1 files changed, 45 insertions, 0 deletions
diff --git a/src/boost/libs/safe_numerics/example/example15.cpp b/src/boost/libs/safe_numerics/example/example15.cpp
new file mode 100644
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+++ b/src/boost/libs/safe_numerics/example/example15.cpp
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+#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, 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;
+}