[Boost-users] [signals2] Warn unused result

Hi, I am using boost::signals2 library for event callback mechanism. The event register callback function returns a boost::signals2::scope_connection object for optional disconnect by the function registering itself. I want to mandate using the returns result (scoped_connection) object by the user. So, I use the gcc attribute "__attribute__( ( warn_unused_result ) )" with the function. The problem is that the compiler does not warn for unused result. Any ideas, why would this happen? I am using Linux with g++ 4.8.4 and c++11 is enabled. Boost version: 1.67.0 I have attached a minimal working example. Thanks, -Deven