trackable_signal can be used to connect() slots that are invoked during subsequent calls to emit(). More...

#include <sigc++/signal.h>

Inheritance diagram for sigc::trackable_signal< T_return(T_arg...)>:

[legend]

Classes
class	accumulated
	Like sigc::trackable_signal but the additional template parameter T_accumulator defines the accumulator type that should be used. More...

Public Types
using	accumulator_type = void

Public Types inherited from sigc::trackable_signal_with_accumulator< T_return, void, T_arg... >
using	slot_type = slot< T_return(T_arg...)>

Public Types inherited from sigc::signal_base
using	size_type = std::size_t

Public Types inherited from sigc::trackable
using	func_destroy_notify = internal::func_destroy_notify

Public Types inherited from sigc::notifiable
using	func_destroy_notify = internal::func_destroy_notify

Public Member Functions
	trackable_signal ()=default

	trackable_signal (const trackable_signal & src)

	trackable_signal (trackable_signal && src)

trackable_signal &	operator= (const trackable_signal & src)

trackable_signal &	operator= (trackable_signal && src)

Public Member Functions inherited from sigc::trackable_signal_with_accumulator< T_return, void, T_arg... >
	trackable_signal_with_accumulator ()=default

	trackable_signal_with_accumulator (const trackable_signal_with_accumulator & src)

	trackable_signal_with_accumulator (trackable_signal_with_accumulator && src)

connection	connect (const slot_type & slot_)
	Add a slot at the end of the list of slots. More...

connection	connect (slot_type && slot_)
	Add a slot at the end of the list of slots. More...

connection	connect_first (const slot_type & slot_)
	Add a slot at the beginning of the list of slots. More...

connection	connect_first (slot_type && slot_)
	Add a slot at the beginning of the list of slots. More...

decltype(auto)	emit (type_trait_take_t< T_arg >... a) const
	Triggers the emission of the signal. More...

decltype(auto)	make_slot () const
	Creates a functor that calls emit() on this signal. More...

decltype(auto)	operator() (type_trait_take_t< T_arg >... a) const
	Triggers the emission of the signal (see emit()). More...

trackable_signal_with_accumulator &	operator= (const trackable_signal_with_accumulator & src)

trackable_signal_with_accumulator &	operator= (trackable_signal_with_accumulator && src)

Public Member Functions inherited from sigc::signal_base
	signal_base () noexcept

	signal_base (const signal_base & src) noexcept

	signal_base (signal_base && src)

	~signal_base ()

void	block (bool should_block=true) noexcept
	Sets the blocking state of all slots in the list. More...

bool	blocked () const noexcept
	Returns whether all slots in the list are blocked. More...

void	clear ()
	Empties the list of slots. More...

bool	empty () const noexcept
	Returns whether the list of slots is empty. More...

signal_base &	operator= (const signal_base & src)

signal_base &	operator= (signal_base && src)

size_type	size () const noexcept
	Returns the number of slots in the list. More...

void	unblock () noexcept
	Unsets the blocking state of all slots in the list. More...

Public Member Functions inherited from sigc::trackable
	trackable () noexcept

	trackable (const trackable & src) noexcept

	trackable (trackable && src) noexcept

	~trackable ()

void	add_destroy_notify_callback (notifiable *data, func_destroy_notify func) const
	Add a callback that is executed (notified) when the trackable object is detroyed. More...

void	notify_callbacks ()
	Execute and remove all previously installed callbacks. More...

trackable &	operator= (const trackable & src)

trackable &	operator= (trackable && src) noexcept

void	remove_destroy_notify_callback (notifiable *data) const
	Remove a callback previously installed with add_destroy_notify_callback(). More...

Additional Inherited Members
Protected Types inherited from sigc::signal_base
using	iterator_type = internal::signal_impl::iterator_type

Protected Member Functions inherited from sigc::signal_base
iterator_type	connect (const slot_base & slot_)
	Adds a slot at the end of the list of slots. More...

iterator_type	connect (slot_base && slot_)
	Adds a slot at the end of the list of slots. More...

iterator_type	connect_first (const slot_base & slot_)
	Adds a slot at the beginning of the list of slots. More...

iterator_type	connect_first (slot_base && slot_)
	Adds a slot at the beginning of the list of slots. More...

std::shared_ptr< internal::signal_impl >	impl () const
	Returns the signal_impl object encapsulating the list of slots. More...

iterator_type	insert (iterator_type i, const slot_base & slot_)
	Adds a slot at the given position into the list of slots. More...

iterator_type	insert (iterator_type i, slot_base && slot_)
	Adds a slot at the given position into the list of slots. More...

Protected Attributes inherited from sigc::signal_base
std::shared_ptr< internal::signal_impl >	impl_
	The signal_impl object encapsulating the slot list. More...

Detailed Description

template<typename T_return, typename... T_arg>
class sigc::trackable_signal< T_return(T_arg...)>

trackable_signal can be used to connect() slots that are invoked during subsequent calls to emit().

Any functor or slot can be passed into connect() or connect_first(). It is converted into a slot implicitly.

If you want to connect one signal to another, use make_slot() to retrieve a functor that emits the signal when invoked.

Be careful if you directly pass one signal into the connect() or connect_first() method of another: a shallow copy of the signal is made and the signal's slots are not disconnected until both the signal and its clone are destroyed, which is probably not what you want!

The template arguments determine the function signature of the emit() function:

T_return The desired return type of the emit() function.
T_arg Argument types used in the definition of emit().

For instance, to declare a trackable_signal whose connected slot returns void and takes two parameters of bool and int:

sigc::trackable_signal<void(bool, int)> some_signal;

To specify an accumulator type the nested class trackable_signal::accumulated can be used.

Example:: void foo(int) {}

sigc::trackable_signal<void(long)> sig;

sig.connect(sigc::ptr_fun(&foo));

sig.emit(19);

sigc::ptr_fun
decltype(auto) ptr_fun(T_return(*func)(T_args...))
Creates a functor of type sigc::pointer_functor which wraps an existing non-member function.
Definition: ptr_fun.h:109

Since libsigc++ 3.4: