Added examples in /example folder (contain snippets for Quickbook), and updates to add typedef static_gcd_t for common factor

example/integer_traits_example.cpp

@@ -0,0 +1,55 @@
+// boost integer_traits_example.cpp 
+
+// Copyright Paul A. Bristow 2015
+// Use, modification and distribution are subject to 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)
+
+// Caution: this file contains Quickbook markup as well as code
+// and comments, don't change any of the special comment markups!
+
+#include <boost/integer_traits.hpp>
+#include <iostream> 
+#include <limits>  // for numeric_limits min and max.
+
+//[integer_traits_example_1
+template<int N>
+void f()
+{ // Entirely contrived templated function.
+  std::cout << N << std::endl; // Do something pointless.
+}
+//] [/integer_traits_example_1]
+
+
+int main()
+{
+  std::cout << "Type int, min =  " 
+    << (std::numeric_limits<int>::min)() 
+    << ", const_min =  " << boost::integer_traits<int>::const_min
+    << std::endl; // Type int, min =  -2147483648, const_min =  -2147483648
+
+//[integer_traits_example_2
+  f<2>();
+//] [/integer_traits_example_2]
+
+//[integer_traits_example_3
+  int i = 2;
+ // f<i>(); // A local variable cannot be used as a non-type argument.
+//] [/integer_traits_example_3]
+
+//[integer_traits_example_4
+  const int ci = 2;
+  f<ci>(); // But a const variable can.
+//] [/integer_traits_example_4]
+//[integer_traits_example_5
+
+  // f<std::numeric_limits<int>::min()>(); // Function call must have a constant value in a constant expression.
+//] [/integer_traits_example_5]
+//[integer_traits_example_6
+
+  f<boost::integer_traits<int>::const_min>();
+//] [/integer_traits_example_6]
+
+} // int main
+