std::is_lvalue_reference — cppreference.com

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Déclaré dans l'en-tête `<type_traits>`
`template< class T > struct is_lvalue_reference;`		(depuis C++11)

Si T est un type de référence lvalue, fournit du membre de constante value true égale. Pour tout autre type, value est false .

Original:

If T is an lvalue reference type, 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


value [ statique Original: static The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. ]	`true` si `T` is an lvalue reference type , `false` autrement Original: `true` if `T` is an lvalue 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. (constante membre statique publique)

Member functions


	convertit l'objet en `bool`, retourne `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. (fonction membre publique)

Member types


Type d' 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>`

Mise en œuvre possible

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

Exemple

#include <iostream>
#include <type_traits>

class A {};

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

Résultat :

false
true
false
false
true
false

Voir aussi


	vérifie si un type est soit lvalue de référence ou' rvalue de référence Original: checks if a type is either lvalue reference or rvalue reference The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe générique) [edit]

	vérifie si un type est' référence rvalue 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. (classe générique) [edit]