is-reference-class.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: is_reference Class	is_reference Class	11/04/2016	type_traits/std::is_reference	is_reference class is_reference	3d9e631f-3092-430c-843e-e914ab58c257

is_reference Class

Tests if type is a reference.

Syntax

template <class Ty>
struct is_reference;

Parameters

Ty
The type to query.

Remarks

An instance of the type predicate holds true if the type Ty is a reference to an object or to a function, otherwise it holds false.

Example

// std__type_traits__is_reference.cpp
// compile with: /EHsc
#include <type_traits>
#include <iostream>

struct trivial
    {
    int val;
    };

int main()
    {
    std::cout << "is_reference<trivial> == " << std::boolalpha
        << std::is_reference<trivial>::value << std::endl;
    std::cout << "is_reference<trivial&> == " << std::boolalpha
        << std::is_reference<trivial&>::value << std::endl;
    std::cout << "is_reference<int()> == " << std::boolalpha
        << std::is_reference<int()>::value << std::endl;
    std::cout << "is_reference<int(&)()> == " << std::boolalpha
        << std::is_reference<int(&)()>::value << std::endl;

    return (0);
    }

is_reference<trivial> == false
is_reference<trivial&> == true
is_reference<int()> == false
is_reference<int(&)()> == true

Requirements

Header: <type_traits>

Namespace: std

See also

<type_traits>
is_pointer Class