1 files changed, 40 insertions, 0 deletions
diff --git a/src/boost/libs/safe_numerics/example/example2.cpp b/src/boost/libs/safe_numerics/example/example2.cpp
new file mode 100644
index 000000000..3866fe854
--- /dev/null
+++ b/src/boost/libs/safe_numerics/example/example2.cpp
@@ -0,0 +1,40 @@
+//  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 <boost/safe_numerics/safe_integer.hpp>
+
+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<int>
+    std::cout << "Using safe numerics" << std::endl;
+    try{
+        using namespace boost::safe_numerics;
+        safe<int> 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;
+}