uv::union_storage< _Ts_ > Class Template Reference

A tagged union that provide a storage space being a standard layout type suited for all its type variants specified in the type list _Ts_. More...

#include "utility.hpp"

Public Types
using	storage_type = typename aligned_union< _Ts_... >::type

Public Member Functions
	union_storage ()=default
	Create an uninitialized union storage.
	union_storage (const union_storage &)=delete
union_storage &	operator= (const union_storage &)=delete
	union_storage (union_storage &&)=delete
union_storage &	operator= (union_storage &&)=delete
template<typename _T_ , typename = std::enable_if_t< is_convertible_to_one_of< _T_, _Ts_... >::value >>
	union_storage (const _T_ &_value)
	Create a union with a copy-initialized value from the specified one.
template<typename _T_ , typename = std::enable_if_t< is_convertible_to_one_of< _T_, _Ts_... >::value >>
	union_storage (_T_ &&_value)
	Create a union with a move-initialized value from the specified value.
const std::type_info *	tag () const noexcept
	The type tag of the stored value. More...
	operator bool () const noexcept
	Equivalent to (tag() != nullptr).
Functions to reinitialize the union storage:
Note The previously stored value is destroyed.
template<typename _T_ >
std::enable_if< is_convertible_to_one_of< _T_, _Ts_... >::value >::type	reset ()
	Reinitialize the union storage with a default value of the one of the type from _Ts_ list that the specified type _T_ is convertible to.
template<typename _T_ , typename... _Args_>
std::enable_if< is_convertible_to_one_of< _T_, _Ts_... >::value >::type	reset (_Args_ &&... _args)
	Ditto but the value is created from the arguments forwarded to the type constructor.
template<typename _T_ >
std::enable_if< is_convertible_to_one_of< _T_, _Ts_... >::value >::type	reset (const _T_ &_value)
	Ditto but the value is copy-created from the specified argument.
template<typename _T_ >
std::enable_if< is_convertible_to_one_of< _T_, _Ts_... >::value >::type	reset (_T_ &&_value)
	Ditto but the value is move-created from the specified argument.
Functions to get the value stored in the union:
template<typename _T_ , typename = std::enable_if_t< is_one_of< _T_, _Ts_... >::value >>
const std::decay< _T_ >::type &	get () const noexcept
template<typename _T_ , typename = std::enable_if_t< is_one_of< _T_, _Ts_... >::value >>
std::decay< _T_ >::type &	get () noexcept

Detailed Description

template<typename... _Ts_>
class uv::union_storage< _Ts_ >

A tagged union that provide a storage space being a standard layout type suited for all its type variants specified in the type list _Ts_.

Only values from the specified set of types _Ts_ are created and stored in the union even though the values of any types that are implicitly convertible to one of the types from _Ts_ list are acceptable for copy- or move-initialization reset() functions.

Note

All the member functions creating a new value in the union from their arguments use the curly brace initialization.

Definition at line 527 of file utility.hpp.

Member Function Documentation

tag()

template<typename... _Ts_>

const std::type_info* uv::union_storage< _Ts_ >::tag ( ) const

inlinenoexcept

The type tag of the stored value.

It's just a pointer referring to the static global constant object returned by the typeid() operator for the type of the value currently stored in this union_storage variable. nullptr is returned if the union is not initialized and is not storing any value.

Definition at line 655 of file utility.hpp.

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The documentation for this class was generated from the following file:

• utility.hpp