std::is_reference – cppreference.com

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definiert in Header `<type_traits>`

`template< class T > struct is_reference;`		(seit C++11)

Wenn T ein Referenz-Typ (lvalue Verweis oder rvalue Referenz) ist, stellt das Mitglied konstanten value gleich true. Für jede andere Art, value ist false .

Original:

If T is a reference type (lvalue reference or rvalue reference), provides the member constant value equal true. For any other type, value is false.

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Inherited from std::integral_constant

Member constants


	`true` wenn `T` is a reference type , `false` anders Original: `true` if `T` is a reference type , `false` otherwise The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (public static Mitglied konstanten)

Member functions


	wandelt das Objekt `bool`, gibt `value` Original: converts the object to `bool`, returns `value` The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (öffentliche Elementfunktion)

Member types


Type Original: Type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.	Definition

`value_type`	`bool`

`type`	`std::integral_constant<bool, value>`

Mögliche Implementierung

template <class T> struct is_reference      : std::false_type {};
template <class T> struct is_reference<T&>  : std::true_type {};
template <class T> struct is_reference<T&&> : std::true_type {};

Beispiel

#include <iostream>
#include <type_traits>

class A {};

int main() 
{
    std::cout << std::boolalpha;
    std::cout << std::is_reference<A>::value << '\n';
    std::cout << std::is_reference<A&>::value << '\n';
    std::cout << std::is_reference<A&&>::value << '\n';
    std::cout << std::is_reference<int>::value << '\n';
    std::cout << std::is_reference<int&>::value << '\n';
    std::cout << std::is_reference<int&&>::value << '\n';
}

Output:

false
true
true
false
true
true

Siehe auch


	prüft, ob ein Typ ist lvalue Verweis Original: checks if a type is lvalue reference The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klassen-Template) [edit]

	prüft, ob ein Typ ist rvalue Verweis Original: checks if a type is rvalue reference The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klassen-Template) [edit]