libsigc++: Libsigc++
libsigc++: 
libsigc++: libsigc++ implements a typesafe callback system for standard C++.
libsigc++: It allows you to define signals and to connect those signals to any
libsigc++: callback function, either global or a member function, regardless of
libsigc++: whether it is static or virtual.
libsigc++: 
libsigc++: 
libsigc++: 
libsigc++: 
libsigc++: