Dune::CopyableOptional< Type > Class Template Reference

A copyable type wrapper that provides copy/move assignment operations for types that are only copy/move constructible. More...

#include <dune/common/copyableoptional.hh>

Public Member Functions
template<class T = Type, std::enable_if_t< std::is_default_constructible_v< T >, int > = 0>
constexpr	CopyableOptional () noexcept(std::is_nothrow_default_constructible_v< T >)
	Implementation of a default constructor, if the Type is itself default constructible. The internal optional contains a value-initialized Type.
template<class T = Type, disableCopyMove< CopyableOptional, T > = 0, std::enable_if_t< std::is_constructible_v< Type, T && >, int > = 0, std::enable_if_t< std::is_convertible_v< T &&, Type >, int > = 0>
constexpr	CopyableOptional (T &&value) noexcept(std::is_nothrow_constructible_v< Type, T && >)
	Construct the internal data from perfect forwarding of the passed arguments. Participates in overload resolution if T is implicitly convertible to Type.
template<class T = Type, disableCopyMove< CopyableOptional, T > = 0, std::enable_if_t< std::is_constructible_v< Type, T && >, int > = 0, std::enable_if_t< not std::is_convertible_v< T &&, Type >, int > = 0>
constexpr	CopyableOptional (T &&value) noexcept(std::is_nothrow_constructible_v< Type, T && >)
	Construct the internal data from perfect forwarding of the passed arguments. Participates in overload resolution if T is not implicitly convertible to Type.
template<class... Args, disableCopyMove< CopyableOptional, Args... > = 0, std::enable_if_t<(sizeof...(Args) > 1), int > = 0, std::enable_if_t< std::is_constructible_v< Type, Args &&... >, int > = 0>
constexpr	CopyableOptional (Args &&... args) noexcept(std::is_nothrow_constructible_v< Type, Args &&... >)
	Construct the internal data from perfect forwarding of the passed arguments.
constexpr	CopyableOptional (const CopyableOptional &)=default
	Copy construct the contained value.
constexpr	CopyableOptional (CopyableOptional &&)=default
	Move construct the contained value.
	~CopyableOptional ()=default
	Default destructor.
constexpr CopyableOptional &	operator= (const CopyableOptional &that) noexcept(std::is_nothrow_copy_assignable_v< Type >||(!std::is_copy_assignable_v< Type > &&std::is_nothrow_copy_constructible_v< Type >))
	Copy assignment in terms of copy constructor.
template<class T = Type, std::enable_if_t< std::is_move_constructible_v< T >, int > = 0>
constexpr CopyableOptional &	operator= (CopyableOptional &&that) noexcept(std::is_nothrow_move_assignable_v< Type >||(!std::is_move_assignable_v< Type > &&std::is_nothrow_move_constructible_v< Type >))
	Move assignment in terms of move constructor.
template<class T = Type, std::enable_if_t< not std::is_same_v< std::decay_t< T >, CopyableOptional >, int > = 0, std::enable_if_t<(std::is_assignable_v< Type &, T >||std::is_constructible_v< Type, T >), int > = 0>
constexpr CopyableOptional &	operator= (T &&value) noexcept(std::is_nothrow_assignable_v< Type &, T >||(!std::is_assignable_v< Type &, T > &&std::is_nothrow_constructible_v< Type, T >))
	Perfect-forwarded assignment or construction.

Detailed Description

template<class Type>
class Dune::CopyableOptional< Type >

A copyable type wrapper that provides copy/move assignment operations for types that are only copy/move constructible.

Some types, like lambdas, LocalFiniteElementCache, Geometries,... provide a copy/move constructor but do not provide a corresponding assignment operator. Mostly, the assignment operators can be implemented in terms of the corresponding constructors. This type wrapper provides these assignment operators by internally wrapping the type into a std::optional.

Template Parameters

Type	The type to be wrapped and equipped with copy operations.

Requirements: Type must be an object type that is copy-constructible

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

• dune/common/copyableoptional.hh