include: Add sanity check for enabled C++11 features

When the library is compiled with C++11 features, it should be checked
that the application is also using C++11-enabled compiler, otherwise the
code cannot compile.

Change-Id: Ia7306a317eb99dbf6161f0760397dd63ed6a1288
diff --git a/include/ndn-cpp/common.hpp b/include/ndn-cpp/common.hpp
index 749cb95..1813b25 100644
--- a/include/ndn-cpp/common.hpp
+++ b/include/ndn-cpp/common.hpp
@@ -13,6 +13,11 @@
 #include "c/common.h"
 
 #if NDN_CPP_HAVE_CXX11
+
+#if (__cplusplus < 201103L)
+#error "NDN-CPP library is configured and compiled in C++11 mode, but the current compiler is not C++11 enabled"
+#endif
+
 // Depending on where ./configure found shared_ptr, define the ptr_lib namespace.
 // We always use ndn::ptr_lib.
 // #if NDN_CPP_HAVE_STD_SHARED_PTR