| description | Learn more about: is_empty Class | ||
|---|---|---|---|
| title | is_empty Class | ||
| ms.date | 11/04/2016 | ||
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| ms.assetid | 44a6fc92-7e55-4fbe-9a24-2a0ce2dccba0 |
Tests if type is an empty class.
template <class Ty>
struct is_empty;Ty
The type to query.
An instance of the type predicate holds true if the type Ty is an empty class, otherwise it holds false.
// std__type_traits__is_empty.cpp
// compile with: /EHsc
#include <type_traits>
#include <iostream>
struct empty
{
};
struct trivial
{
int val;
};
int main()
{
std::cout << "is_empty<trivial> == " << std::boolalpha
<< std::is_empty<trivial>::value << std::endl;
std::cout << "is_empty<empty> == " << std::boolalpha
<< std::is_empty<empty>::value << std::endl;
std::cout << "is_empty<int> == " << std::boolalpha
<< std::is_empty<int>::value << std::endl;
return (0);
}is_empty<trivial> == false
is_empty<empty> == true
is_empty<int> == false
Header: <type_traits>
Namespace: std