std::experimental::any_cast

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Technical specifications

Filesystem library (filesystem TS)

Library fundamentals (library fundamentals TS)

Library fundamentals 2 (library fundamentals TS v2)

Library fundamentals 3 (library fundamentals TS v3)

Extensions for parallelism (parallelism TS)

Extensions for parallelism 2 (parallelism TS v2)

Extensions for concurrency (concurrency TS)

Extensions for concurrency 2 (concurrency TS v2)

Concepts (concepts TS)

Ranges (ranges TS)

Reflection (reflection TS)

Mathematical special functions (special functions TR)

 

Library fundamentals

experimental::optional

experimental::any

experimental::basic_string_view

experimental::sample

experimental::shared_ptr

experimental::weak_ptr

experimental::apply

experimental::invocation_typeexperimental::raw_invocation_type

experimental::search

experimental::default_searcherexperimental::make_default_searcher

experimental::boyer_moore_searcherexperimental::make_boyer_moore_searcher

experimental::boyer_moore_horspool_searcherexperimental::make_boyer_moore_horspool_searcher

Type-erased and polymorphic allocators

Variable templates for type traits

 

std::experimental::any

Member functions

any::any

any::operator=

Modifiers

any::clear

any::swap

Observers

any::empty

any::type

Non-member functions

swap(std::experimental::any)

any_cast

 

template<class ValueType>     ValueType any_cast(const any& operand);	(1)	(library fundamentals TS)
template<class ValueType>     ValueType any_cast(any& operand);	(2)	(library fundamentals TS)
template<class ValueType>     ValueType any_cast(any&& operand);	(3)	(library fundamentals TS)
template<class ValueType>     const ValueType* any_cast(const any* operand) noexcept;	(4)	(library fundamentals TS)
template<class ValueType>     ValueType* any_cast(any* operand) noexcept;	(5)	(library fundamentals TS)

Performs type-safe access to the contained object.

For (1-3), the program is ill-formed if ValueType is not a reference and std::is_copy_constructible<ValueType>::value is false.

Parameters

operand

-

target any object

Return value

1) Returns *any_cast<std::add_const_t<std::remove_reference_t<ValueType>>>(&operand).

2-3) Returns *any_cast<std::remove_reference_t<ValueType>>(&operand).

4-5) If operand is not a null pointer, and the typeid of the requested ValueType matches that of the contents of operand, a pointer to the value contained by operand, otherwise a null pointer.

Exceptions

1-3) Throws bad_any_cast if the typeid of the requested ValueType does not match that of the contents of operand.