first version with working policies

promotion pollicy
exception policy
improved documentation

examples/example6.cpp

@@ -0,0 +1,50 @@
+#include <cassert>
+#include <stdexcept>
+#include <sstream>
+#include <iostream>
+
+#include "../include/safe_integer.hpp"
+
+void detected_msg(bool detected){
+    std::cout << (detected ? "error detected!" : "error NOT detected! ") << std::endl;
+}
+
+int main(int argc, const char * argv[]){
+    // problem: checking of externally produced value can be overlooked
+    std::cout << "example 6: ";
+    std::cout << "checking of externally produced value can be overlooked" << std::endl;
+    std::cout << "Not using safe numerics" << std::endl;
+
+    std::istringstream is("12317289372189 1231287389217389217893");
+
+    int x, y, z;
+    is >> x >> y; // get integer values from the user
+    z = x + y;
+    std::cout << z << std::endl;  // display sum of the values
+    detected_msg(false);
+    
+    // solution: asign externally retrieved values to safe equivalents
+    std::cout << "Using safe numerics" << std::endl;
+    {
+        using namespace boost::numeric;
+        safe<int> x, y, z;
+        is.seekg(0);
+        try{
+            is >> x >> y; // get integer values from the user
+            detected_msg(false);
+        }
+        catch(std::range_error & e){
+            std::cout << e.what() << std::endl;
+            detected_msg(true);
+        }
+        try{
+            z = x + y;
+            detected_msg(false);
+        }
+        catch(std::exception e){
+            std::cout << z << std::endl;  // display sum of the values
+            detected_msg(true);
+        }
+    }
+    return 0;
+}