Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/src/boost/libs/safe_numerics/example/example4.cpp b/src/boost/libs/safe_numerics/example/example4.cpp
new file mode 100644
index 000000000..d3b8eae77
--- /dev/null
+++ b/src/boost/libs/safe_numerics/example/example4.cpp
@@ -0,0 +1,57 @@
+//  Copyright (c) 2018Robert 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(){
+    std::cout << "example 4: ";
+    std::cout << "implicit conversions change data values" << std::endl;
+    std::cout << "Not using safe numerics" << std::endl;
+    
+    // problem: implicit conversions change data values
+    try{
+        signed int   a{-1};
+        unsigned int b{1};
+        std::cout << "a is " << a << " b is " << b << '\n';
+        if(a < b){
+            std::cout << "a is less than b\n";
+        }
+        else{
+            std::cout << "b is less than a\n";
+        }
+        std::cout << "error NOT detected!" << std::endl;
+    }
+    catch(const std::exception &){
+        // never arrive here - just produce the wrong answer!
+        std::cout << "error detected!" << std::endl;
+        return 1;
+    }
+
+    // solution: replace int with safe<int> and unsigned int with safe<unsigned int>
+    std::cout << "Using safe numerics" << std::endl;
+    try{
+        using namespace boost::safe_numerics;
+        safe<signed int>   a{-1};
+        safe<unsigned int> b{1};
+        std::cout << "a is " << a << " b is " << b << '\n';
+        if(a < b){
+            std::cout << "a is less than b\n";
+        }
+        else{
+            std::cout << "b is less than a\n";
+        }
+        std::cout << "error NOT detected!" << std::endl;
+        return 1;
+    }
+    catch(const std::exception & e){
+        // never arrive here - just produce the correct answer!
+        std::cout << e.what() << std::endl;
+        std::cout << "error detected!" << std::endl;
+    }
+    return 0;
+}