There is a mailing list,

[libsigc-list@gnome.org](http://mail.gnome.org/mailman/listinfo/libsigc-list) for libsigc++, to serve as

a design discussion area as well as a place to report bugs. To subscribe, use the web

[page](http://mail.gnome.org/mailman/listinfo/libsigc-list).

Members can post directly, but all other traffic is moderated.

There is an archive of messages,

[here](http://mail.gnome.org/archives/libsigc-list/).

Patches should be added to bugzilla bugs.

See the list of [open libsigc++ bugs](http://bugzilla.gnome.org/buglist.cgi?product=libsigc%2B%2B&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_status=NEEDINFO") ,or [submit a new libsigc++ bug]("http://bugzilla.gnome.org/enter_bug.cgi?product=libsigc%2B%2B).

We also accept pull requests via the [libsigc++ mirror on GitHub](https://github.com/GNOME/libsigcplusplus).

libsigc++ is in the [libsigcplusplus](http://git.gnome.org/browse/libsigcplusplus/) module in GNOME's git repository.

There is also a [libsigc++ mirror on GitHub](https://github.com/GNOME/libsigcplusplus).

We have both [tutorial-style](http://developer.gnome.org/libsigc++-tutorial/stable/)

and [reference](http://developer.gnome.org/libsigc++/stable/) documentation.

For those which just want a quick look at the terms used in

the system, glance over the [glossary](glossary.shtml)

**adaptor** *(noun)* - A function which alters a slot’s

signature.

**bind** *(verb)* - To fix a value of a callback's argument in the

STL sense.

**call** *(verb)* - The process of invoking a callback or slot.

**callback** *(noun)* - A function or a member function which will

be called when a signal is emitted. A slot specifies the callback and any extra

data, such as the object instance, and extra parameters.

**connect** *(verb)* - The process of specifying the callback

which will be called when the signal is emitted.

**emit** *(verb)* - When a signal is emitted, the connected slots

will be called.

**factory** *(noun)* - A function which takes a set of arguments and

produces a different object based on those arguments.

**handle** *(noun)* - A safe version of a pointer.

**marshaller** *(noun)* - When a signal has a return value, and

several slots are connected to that signal, each one returning a value, then a

marshaller chooses one single return value.

**safe** *(adj)* - Any structure which falls back into uninitalized state

when its related resources are destroyed. Safe resources can be

held throughout the program. Unsafe resources may point to freed

memory.

**signal** *(noun)* - An object to which callback slots can be

connected. When the signal is emitted, each callback will be invoked. The

signal and the connected slots have a specific return type and parameter types.

**signal handler** *(noun)* - Another name for a callback.

**signature** *(noun)* - The return type of a function together with

the argument types of that function.

**slot** *(noun)* - A safe version of a callback.

libsigc++ implements a typesafe callback system for standard C++. It

allows you to define signals and to connect those signals to any

callback function, either global or a member function, regardless of

whether it is static or virtual.

It also contains adaptor classes for connection of dissimilar

callbacks and has an ease of use unmatched by other

C++ callback libraries. Libsigc++ is licensed under

the GNU Library General Public License, [LGPL](http://www.gnu.org/copyleft/lgpl.html).

* Compile time typesafe callbacks (faster than run time checks)

* Typesafety violations report 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 seg faults)

* 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

* Most C++ compilers can be used. libsigc++ version 2.5.1 and later require a compiler with C++11 support

See the [NEWS](https://git.gnome.org/browse/libsigcplusplus/tree/NEWS) file in git.

The original library was composed by Tero Pulkkinen for the

gtkmm system, a C++ wrapper for the Gtk+ widget set. The revised

library was written and mantained by Karl Nelson. Special thanks

to Esa Pulkkinen for development tips.

The 1.2 phase was maintained by Murray Cumming after Karl provided the initial 1.2 code.

A long 1.9 phase led to the major release 2.0, previously maintained by Martin Schulze,

and then maintained by Murray Cumming and Kjell Ahlstedt.

Then libsigc++ was rewritten for C++14 using variadic templates, for major release 3.0,

currently maintained by Murray Cumming and Kjell Ahlstedt.

Libsigc++ is licensed under the [GNU Library General Public License](https://www.gnu.org/licenses/lgpl-3.0-standalone.html)

for all platforms. Our intent in licensing it in this way is to

provide it for use through shared libraries in all projects both

open and proprietary. Other GNU projects may of course integrate

and link in a static manner. The full body of the license is

provided for your inspection.

This is the only license which grants you use of the software, so

if you do not agree to its terms, you may not use this software.

Libsigc++ is part of the greater GNOME code base.

* [gtkmm widget wrapper](http://www.gtkmm.org)

* [GTK+ widget set](http://www.gtk.org)

* [Gnome project](http://www.gnome.org)

There are a number of other C++ callback systems

and publications on construction of callback systems.

* [Boost Signals](http://www.boost.org/doc/html/signals.html)

* Trolltech signal system (part of [Qt widget set](http://www.qt.io/))

* (Send us a link you find worth mentioning here.)

Here is a list of some of the projects that use libsigc++.

(Have a project which is using libsigc++? Mail us.)

* [glibmm and gtkmm](http://www.gtkmm.org)

* [Libpropc++: Creating and effective using properties in C++](http://sourceforge.net/projects/libpropc/)

* [Yehia: Extension library with support for cross-threaded signal emission.](http://ucxx.sourceforge.net/)

* [GFC: Alternative C++ wrapper for the GTK+ widget set.](http://gfc.sourceforge.net/)

* [Libuta](http://sourceforge.net/projects/libuta/)

* [The WorldForge Project](http://www.worldforge.org/)