xtd::delegate< result_t()> Class Template Reference

#include <delegate.h>

Definition

template<typename result_t>
class xtd::delegate< result_t()>

Represents a delegate, which is a data structure that refers to a static method or to a class instance && an instance method of that class.

Namespace

xtd

Library

xtd.core

Examples

The following example shows how to define a delegate named my Method delegate. Instances of this delegate are created for an instance method && a static method of the nested mySampleClass class. The delegate for the instance method requires an instance of mySampleClass. The mySampleClass instance is saved in a variable named mySC.

#include <xtd/xtd>
 
using namespace std;
using namespace xtd;
 
void goodbye(const ustring& s) {
  console::write_line("Goodbye {}", s);
}
 
class object {
public:
  void hello(const ustring& s) {
    console::write_line("Hello {}", s);
  }
};
 
int main() {
  using example_function = delegate<void(const ustring&)>;
  ::object instance;
  ustring str("World");
  //example_function f = {instance, &::object::hello};
  example_function f = {std::bind(&::object::hello, &instance, std::placeholders::_1)};
 
  // equivalent to instance.hello(str)
  f(str);
  f = goodbye;
  
  // equivalent to goodbye(str)
  f(str);
  return 0;
}
 
// This code produces the following output:
//
// Hello, World
// Goodbye, World

Inherits xtd::object.

Public Types
using	function_t = std::function< result_t()>
	function_t pointer type

Public Member Functions
	delegate ()=default
	Initializes an empty delegate.
	delegate (const delegate &delegate) noexcept
	Initializes a delegate that invokes the specified delegate instance.
template<typename object1_t , typename object2_t >
	delegate (const object1_t &object, result_t(object2_t::*method)() const) noexcept
	Initializes a delegate that invokes the specified instance method on the specified class instance.
template<typename object1_t , typename object2_t >
	delegate (const object1_t &object, result_t(object2_t::*method)()) noexcept
	Initializes a delegate that invokes the specified instance method on the specified class instance.
void	clear ()
	Clear delegates array.
const std::vector< function_t > &	functions () const
	Gets the delegates array.
result_t	invoke () const
	invokes the method represented by the current delegate.
bool	is_empty () const noexcept
	Return if the delegate is empty.
bool	operator!= (const delegate &delegate) const
	Determines whether this instance and another specified delegateType object have the same value.
result_t	operator() () const
	invokes the method represented by the current delegate.
delegate &	operator= (const function_t &function) noexcept
bool	operator== (const delegate &delegate) const noexcept
	Determines whether this instance and another specified delegateType object have the same value.
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
template<typename object_t >
std::unique_ptr< object_t >	memberwise_clone () const
	Gets the type of the current instance.
virtual xtd::ustring	to_string () const noexcept
	Returns a std::string that represents the current object.

Static Public Member Functions
static delegate	combine (const delegate &a, const delegate &b) noexcept
	Concatenates the invocation lists of two delegates.
static delegate	combine (const std::vector< delegate > &delegates) noexcept
	Concatenates the invocation lists of an array of delegates.
static delegate	remove (const delegate &source, const delegate &value) noexcept
	removes the last occurrence of the invocation list of a delegate from the invocation list of another delegate.
static delegate	remove_all (const delegate &source, const delegate &value) noexcept
	removes all occurrences of the invocation list of a delegate from the invocation list of another delegate.
Static Public Member Functions inherited from xtd::object
static bool	equals (const object &object_a, const object &object_b) noexcept
	Determines whether the specified object instances are considered equal.
static bool	reference_equals (const object &object_a, const object &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Member Typedef Documentation

function_t

template<typename result_t >

using xtd::delegate< result_t()>::function_t = std::function <result_t()>

function_t pointer type

Constructor & Destructor Documentation

delegate() [1/4]

template<typename result_t >

xtd::delegate< result_t()>::delegate ( )

default

Initializes an empty delegate.

delegate() [2/4]

template<typename result_t >

xtd::delegate< result_t()>::delegate ( const delegate< result_t()> &  delegate )

inlinenoexcept

Initializes a delegate that invokes the specified delegate instance.

Parameters

delegate

The delegate instance.

delegate() [3/4]

template<typename result_t >

template<typename object1_t , typename object2_t >

xtd::delegate< result_t()>::delegate ( const object1_t &  object, result_t(object2_t::*)() const  method  )

inlinenoexcept

Initializes a delegate that invokes the specified instance method on the specified class instance.

Parameters

object	the class instance.
function	the method instance.

delegate() [4/4]

template<typename result_t >

template<typename object1_t , typename object2_t >

xtd::delegate< result_t()>::delegate ( const object1_t &  object, result_t(object2_t::*)()  method  )

inlinenoexcept

Initializes a delegate that invokes the specified instance method on the specified class instance.

Parameters

object	the class instance.
function	the method instance.

Member Function Documentation

clear()

template<typename result_t >

void xtd::delegate< result_t()>::clear ( )

inline

Clear delegates array.

combine() [1/2]

template<typename result_t >

static delegate xtd::delegate< result_t()>::combine ( const delegate< result_t()> &  a, const delegate< result_t()> &  b  )

inlinestaticnoexcept

Concatenates the invocation lists of two delegates.

Parameters

a	The delegate whose invocation list comes first.
b	The delegate whose invocation list comes second.

Returns

delegateType A new delegate with an invocation list that concatenates the invocation lists of a and b in that order. Returns a if b is null, returns b if a is a null reference, and returns a null reference if both a and b are null references.

Remarks

The invocation list can contain duplicate entries; that is, entries that refer to the same method on the same object.

combine() [2/2]

template<typename result_t >

static delegate xtd::delegate< result_t()>::combine ( const std::vector< delegate< result_t()> > &  delegates )

inlinestaticnoexcept

Concatenates the invocation lists of an array of delegates.

Parameters

delegates

The array of delegates to combine.

Returns

Delegate A new delegate with an invocation list that concatenates the invocation lists of the delegates in the delegates array. Returns null if delegates is null, if delegates contains zero elements, || if every entry in delegates is null.

Remarks

If the delegates array contains entries that are null, those entries are ignored.

The invocation list can contain duplicate entries; that is, entries that refer to the same method on the same object.

functions()

template<typename result_t >

const std::vector< function_t > & xtd::delegate< result_t()>::functions ( ) const

inline

Gets the delegates array.

Returns

The delegates array.

invoke()

template<typename result_t >

result_t xtd::delegate< result_t()>::invoke ( ) const

inline

invokes the method represented by the current delegate.

Parameters

arguments

The parameter list.

Returns

result_t The return value.

is_empty()

template<typename result_t >

bool xtd::delegate< result_t()>::is_empty ( ) const

inlinenoexcept

Return if the delegate is empty.

Returns

bool Return true if delegate is empty; otherwise false.

operator!=()

template<typename result_t >

bool xtd::delegate< result_t()>::operator!= ( const delegate< result_t()> &  delegate ) const

inline

Determines whether this instance and another specified delegateType object have the same value.

Parameters

value

The delegateType to compare.

Returns

bool true if the value of this instance is the same as the value of value; otherwise, false.

operator()()

template<typename result_t >

result_t xtd::delegate< result_t()>::operator() ( ) const

inline

invokes the method represented by the current delegate.

Parameters

arguments

The parameter list.

Returns

result_t The return value.

operator==()

template<typename result_t >

bool xtd::delegate< result_t()>::operator== ( const delegate< result_t()> &  delegate ) const

inlinenoexcept

Determines whether this instance and another specified delegateType object have the same value.

Parameters

value

The delegateType to compare.

Returns

bool true if the value of this instance is the same as the value of value; otherwise, false.

remove()

template<typename result_t >

static delegate xtd::delegate< result_t()>::remove ( const delegate< result_t()> &  source, const delegate< result_t()> &  value  )

inlinestaticnoexcept

removes the last occurrence of the invocation list of a delegate from the invocation list of another delegate.

Parameters

source	The delegate from which to remove the invocation list of value.
value	The delegate that supplies the invocation list to remove from the invocation list of source.

Returns

delegate A new delegate with an invocation list formed by taking the invocation list of source and removing the last occurrence of the invocation list of value, if the invocation list of value is found within the invocation list of source. Returns source if value is null || if the invocation list of value is ! found within the invocation list of source. Returns a null reference if the invocation list of value is equal to the invocation list of source || if source is a null reference.

Remarks

If the invocation list of value matches a contiguous set of elements in the invocation list of source, then the invocation list of value is said to occur within the invocation list of source. If the invocation list of value occurs more than once in the invocation list of source, the last occurrence is removed.

remove_all()

template<typename result_t >

static delegate xtd::delegate< result_t()>::remove_all ( const delegate< result_t()> &  source, const delegate< result_t()> &  value  )

inlinestaticnoexcept

removes all occurrences of the invocation list of a delegate from the invocation list of another delegate.

Parameters

source	The delegate from which to remove the invocation list of value.
value	The delegate that supplies the invocation list to remove from the invocation list of source.

Returns

delegate A new delegate with an invocation list formed by taking the invocation list of source && removing all occurrences of the invocation list of value, if the invocation list of value is found within the invocation list of source. Returns source if value is null || if the invocation list of value is ! found within the invocation list of source. Returns a null reference if the invocation list of value is equal to the invocation list of source, if source contains only a series of invocation lists that are equal to the invocation list of value, || if source is a null reference.

Remarks

If the invocation list of value matches a contiguous set of elements in the invocation list of source, then the invocation list of value is said to occur within the invocation list of source. If the invocation list of value occurs more than once in the invocation list of source, all occurrences are removed.

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The documentation for this class was generated from the following file:

• xtd.core/include/xtd/delegate.h