any-class.md

description	title	ms.date	f1_keywords	helpviewer_keywords	no-loc
Learn more about the std::any class from the C++ Standard Library.	any class	09/20/2021	any/std::any any/std::any::emplace any/std::any::has_value any/std::any::reset any/std::any::swap any/std::any::type	any/std::any any/std::any::emplace any/std::any::has_value any/std::any::reset any/std::any::swap any/std::any::type	any std class

any class

An any object either stores an instance of a type that satisfies the constructor requirements, or it has no value. Whether it has a stored instance, or no value, is called the state of the any object.

The stored instance is called the contained value. Two any objects have the same state if either they both have no value, or both have a contained value and those values are the same.

Syntax

class any;

Members

Constructors

Name	Description
any	Constructs an object of type any.

Functions

Name	Description
emplace	Sets an any value.
has_value	Returns true if any has a value.
reset	Resets an any.
swap	Exchanges two any objects.
type	Returns the any type.

Operators

Name	Description
operator=	Replaces the any with a copy of another any.

any

Constructs an object of type any. Also includes a destructor.

constexpr any() noexcept;
any(const any& other);
any(any&& other) noexcept;
template <class T>
    any(T&& value);
template <class T, class... Args>
    explicit any(in_place_type_t<T>, Args&&...);
template <class T, class U, class... Args>
    explicit any(in_place_type_t<T>, initializer_list<U>, Args&&...);

~any();

emplace

Sets an any value.

template <class T, class... Args>
    decay_t<T>& emplace(Args&& ...);
template <class T, class U, class... Args>
    decay_t<T>& emplace(initializer_list<U>, Args&&...);

has_value

Returns true if the any object has a value.

bool has_value() const noexcept;

operator=

Replaces the any content with a copy of another any.

any& operator=(const any& right);
any& operator=(any&& right) noexcept;
template <class T>
    any& operator=(T&& right);

Parameters

right
The any being copied into this any.

reset

Resets an any.

void reset() noexcept;

swap

Exchanges two any objects.

void swap(any& rhs) noexcept;

type

Returns the any type.

const type_info& type() const noexcept;

Requirements

Header: <any>

Namespace: std

Standard: C++17 (Use at least /std:c++17 to compile.)

See also

<any>
any_cast
make_any
swap
bad_any_cast