libsigc++: libsigc++ Reference Manual

# libsigc++ Reference Manual

### 2.2.8

## Description

libsigc++ provides a typesafe (at compile time) callback system for standard C++. It allows you to define signals and to connect those signals to any callback function, either a global or a member function, regardless of whether it is static or virtual. It also contains adaptor classes for connection of dissimilar callbacks.

For instance, see the Signals, Functors, Slots, Adaptors, and Lambdas.

See also the libsigc++ tutorial, the the libsigc++ website, and the Signals appendix of the Programming with gtkmm book.

## Features

- Compile-time typesafe callbacks (also faster than run time checks)
- Type-safety violations report the line number correctly with template names (no tracing template failures into headers)
- No compiler extensions or meta compilers required
- Proper handling of dynamic objects and signals (deleted objects will not cause crashes)
- Extendable API at any level: signal, slot, connection and trackable
- Extensions do not require alteration of basic components
- User-definable accumulators
- A variety of adaptors to change the callback signature: bind, hide, retype, compose and lambda call groups

## Basic Usage

Include the libsigc++ header:

     #include <sigc++/sigc++.h>

(You may include individual headers, such as `sigc++/bind`.h instead.)

If your source file is `program.cc`, you can compile it with:

     g++ program.cc -o program `pkg-config --cflags --libs sigc++-2.0`

Alternatively, if using autoconf, use the following in `configure.ac:`

     PKG_CHECK_MODULES([LIBSIGC], [sigc++-2.0])

Then use the generated `LIBSIGC_CFLAGS` and `LIBSIGC_LIBS` variables in the project `Makefile.am` files. For example:

     program_CPPFLAGS = $(LIBSIGC_CFLAGS)
     program_LDADD = $(LIBSIGC_LIBS)