track_obj(), track_object()

sigc::track_object() tracks trackable objects, referenced from a functor. More...

Classes
class	sigc::track_obj_functor< T_functor, T_obj >
	track_obj_functor wraps a functor and stores a reference to a trackable object. More...

Functions
template<typename T_functor, typename... T_obj>
decltype(auto)	sigc::track_obj (const T_functor & func, const T_obj &... obj)
	Creates an adaptor of type sigc::track_obj_functor which wraps a functor.
template<typename T_functor, typename T_obj1, typename... T_objs>
decltype(auto)	sigc::track_object (const T_functor & func, const T_obj1 & obj1, const T_objs &... objs)
	Creates an adaptor of type sigc::track_obj_functor which wraps a functor.

Detailed Description

sigc::track_object() tracks trackable objects, referenced from a functor.

It can be useful when you assign a C++11 lambda expression or a std::function<> to a slot, or connect it to a signal, and the lambda expression or std::function<> contains references to sigc::trackable derived objects.

The functor returned by sigc::track_object() is formally an adaptor, but it does not alter the signature, return type or behaviour of the supplied functor.

track_obj() is a deprecated alternative to track_object().

Example:

struct bar : public sigc::trackable {};
sigc::signal<void()> some_signal;
void foo(bar&);
{
  bar some_bar;
  some_signal.connect([&some_bar](){ foo(some_bar); });
    // NOT disconnected automatically when some_bar goes out of scope
  some_signal.connect(sigc::track_object([&some_bar](){ foo(some_bar); }, some_bar);
    // disconnected automatically when some_bar goes out of scope
}

Function Documentation

track_obj()

template <typename T_functor, typename... T_obj>

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

inline

Creates an adaptor of type sigc::track_obj_functor which wraps a functor.

Parameters

func	Functor that shall be wrapped.
obj	Trackable objects.

Returns

Adaptor that executes func() on invocation.

Since libsigc++ 2.4

Deprecated

Use sigc::track_object() instead.

track_object()

template <typename T_functor, typename T_obj1, typename... T_objs>

decltype(auto) sigc::track_object ( const T_functor & func, const T_obj1 & obj1, const T_objs &... objs )

inline

Creates an adaptor of type sigc::track_obj_functor which wraps a functor.

Parameters

func	Functor that shall be wrapped.
obj1	Trackable object, derived directly or indirectly from sigc::trackable.
objs	Zero or more trackable objects, derived directly or indirectly from sigc::trackable.

Returns

Adaptor that executes func() on invocation.

Since libsigc++ 3.4