libsigc++  3.0.4
New API in libsigc++ 2.4

sigc::signal_base Member sigc::signal_base::blocked () const noexcept

sigc::signal_base Member sigc::signal_base::block (bool should_block=true) noexcept

sigc::signal_base Member sigc::signal_base::unblock () noexcept

Module track_obj

sigc::track_obj_functor Class sigc::track_obj_functor< T_functor, T_obj >

sigc Member sigc::track_obj (const T_functor& func, const T_obj&... obj)