is-same-class.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: is_same Class	is_same Class	11/04/2016	type_traits/std::is_same	is_same class is_same	d9df6c1d-c270-4ec2-802a-af275648dd1d

is_same Class

Tests if two types are the same.

Syntax

template <class Ty1, class Ty2>
struct is_same;

Parameters

Ty1
The first type to query.

Ty2
The second type to query.

Remarks

An instance of the type predicate holds true if the types Ty1 and Ty2 are the same type, otherwise it holds false.

Example

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

struct base
    {
    int val;
    };

struct derived
    : public base
    {
    };

int main()
    {
    std::cout << "is_same<base, base> == " << std::boolalpha
        << std::is_same<base, base>::value << std::endl;
    std::cout << "is_same<base, derived> == " << std::boolalpha
        << std::is_same<base, derived>::value << std::endl;
    std::cout << "is_same<derived, base> == " << std::boolalpha
        << std::is_same<derived, base>::value << std::endl;
    std::cout << "is_same<int, int> == " << std::boolalpha
        << std::is_same<int, int>::value << std::endl;
    std::cout << "is_same<int, const int> == " << std::boolalpha
        << std::is_same<int, const int>::value << std::endl;

    return (0);
    }

is_same<base, base> == true
is_same<base, derived> == false
is_same<derived, base> == false
is_same<int, int> == true
is_same<int, const int> == false

Requirements

Header: <type_traits>

Namespace: std

See also

<type_traits>
is_convertible Class
is_base_of Class