Constructor for std::exception does not take string argument.

Author: rolftimmermans

zmq_addon.hpp

@@ -222,7 +222,7 @@ class multipart_t
     {
         static_assert(!std::is_same<T, std::string>::value, "Use popstr() instead of poptyp<std::string>()");
         if (sizeof(T) != m_parts.front().size())
-            throw std::exception("Invalid type, size does not match the message size");
+            throw std::runtime_error("Invalid type, size does not match the message size");
         T type = *m_parts.front().data<T>();
         m_parts.pop_front();
         return type;