Libsigc++ -- The Typesafe Callback Framework for C++

This library implements a full callback system for use in widget libraries,
abstract interfaces, and general programming.

To get a good overview of how to use the library, read
/usr/local/share/doc/libsigc++/signals.

WWW: https://libsigcplusplus.github.io/libsigcplusplus/index.html