is_reference Class
The latest version of this topic can be found at 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