Acts::AnyBase< SbSize, Copyable, Base > Class Template Reference

Small opaque type-erased type with configurable small buffer optimization. More...

#include <Acts/Utilities/Any.hpp>

Inheritance diagram for Acts::AnyBase< SbSize, Copyable, Base >:

Collaboration diagram for Acts::AnyBase< SbSize, Copyable, Base >:

Public Member Functions
	AnyBase (AnyBase &&other) noexcept(detail::kAnyNoexcept)
	Move constructor.
	AnyBase (const AnyBase &)=delete
	Copy constructor deleted when Copyable is false (move-only variant).
	AnyBase (const AnyBase &other)
	Copy constructor (only when Copyable is true).
template<typename T, typename... Args> requires (isStorable<std::decay_t<T>>())
	AnyBase (std::in_place_type_t< T >, Args &&... args)
	Construct with in-place type construction.
template<typename T> requires (!std::is_base_of_v<AnyBaseAll, std::decay_t<T>> && isStorable<std::decay_t<T>>())
	AnyBase (T &&value)
	Construct from any value type.
template<typename T>
T &	as ()
	Get reference to stored value of specified type.
template<typename T>
const T &	as () const
	Get const reference to stored value of specified type.
template<typename B = Base> requires (!std::is_void_v<B>)
B *	asBase ()
	Get a pointer to the stored value as Base*, regardless of its concrete type.
template<typename B = Base> requires (!std::is_void_v<B>)
const B *	asBase () const
	Get a const pointer to the stored value as Base*.
template<typename T>
T *	asPtr ()
	Get pointer to stored value of specified type.
template<typename T>
const T *	asPtr () const
	Get const pointer to stored value of specified type.
template<typename T, typename... Args> requires (isStorable<std::decay_t<T>>())
T &	emplace (Args &&... args)
	Construct a new value in place, destroying any existing value.
	operator bool () const
	Check if the AnyBase contains a value.
template<typename B = Base> requires (!std::is_void_v<B>)
B &	operator* ()
	Dereference to the stored value as Base&.
template<typename B = Base> requires (!std::is_void_v<B>)
const B &	operator* () const
	Dereference to the stored value as const Base&.
template<typename B = Base> requires (!std::is_void_v<B>)
B *	operator-> ()
	Member access on the stored value as Base*.
template<typename B = Base> requires (!std::is_void_v<B>)
const B *	operator-> () const
	Member access on the stored value as const Base*.
AnyBase &	operator= (AnyBase &&other) noexcept(detail::kAnyNoexcept)
	Move assignment operator.
AnyBase &	operator= (const AnyBase &)=delete
	Copy assignment deleted when Copyable is false (move-only variant).
AnyBase &	operator= (const AnyBase &other)
	Copy assignment operator (only when Copyable is true).
template<typename T>
T	take ()
	Move the stored value out.
const std::type_info *	typeInfo () const
	Type info of the stored value.

Detailed Description

template<std::size_t SbSize, bool Copyable = true, typename Base = void>
class Acts::AnyBase< SbSize, Copyable, Base >

Small opaque type-erased type with configurable small buffer optimization.

Template Parameters

SbSize	Size of the internal buffer for small buffer optimization
Copyable	If true, stored types must be copyable and AnyBase is copyable. If false, move-only types are allowed and AnyBase is move-only (copy constructor and copy assignment are deleted).

Note

Type requirements when Copyable is true:

• All stored types must be copy constructible and copy assignable.
• Types stored locally (sizeof(T) <= SbSize) must also be move constructible and move assignable because local moves use move operations when not trivially movable (trivial moves fall back to buffer copies).
• Types stored on the heap (sizeof(T) > SbSize) are moved by stealing the pointer, so no move operations are required in that case.

Type requirements when Copyable is false:

• All stored types must be move constructible.
• Types stored locally must also be move assignable.
• Heap-allocated types only need move constructible (pointer steal).

In summary:

• Local storage: values live inside the internal buffer; moves may invoke move operations or buffer copies; copies use copy operations or buffer copies when trivial.
• Heap storage: values are allocated on the heap; moves transfer ownership of the pointer; copies allocate and copy-construct the pointee.

Constructor & Destructor Documentation

AnyBase() [1/4]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T, typename... Args>
requires (isStorable<std::decay_t<T>>())

Acts::AnyBase< SbSize, Copyable, Base >::AnyBase ( std::in_place_type_t< T > , Args &&... args )

explicit

Construct with in-place type construction.

Template Parameters

T	Type to construct
Args	Constructor argument types

Parameters

args	Arguments to forward to T's constructor

AnyBase() [2/4]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T>
requires (!std::is_base_of_v<AnyBaseAll, std::decay_t<T>> && isStorable<std::decay_t<T>>())

Acts::AnyBase< SbSize, Copyable, Base >::AnyBase ( T && value )

explicit

Construct from any value type.

Template Parameters

T	Type of the value to store

Parameters

value

Value to store in the Any

Note

Not noexcept: storing a type larger than the small buffer allocates on the heap (may throw std::bad_alloc) and the stored type's own constructor may throw.

AnyBase() [3/4]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

Acts::AnyBase< SbSize, Copyable, Base >::AnyBase

(

const AnyBase< SbSize, Copyable, Base > &

other

)

Copy constructor (only when Copyable is true).

Parameters

other

The AnyBase to copy from

Note

Not noexcept: copying a heap-allocated value allocates (may throw std::bad_alloc) and the stored type's copy constructor may throw.

AnyBase() [4/4]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

Acts::AnyBase< SbSize, Copyable, Base >::AnyBase ( AnyBase< SbSize, Copyable, Base > && other )

noexcept

Move constructor.

Parameters

other

The AnyBase to move from

Member Function Documentation

as() [1/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T>

T & Acts::AnyBase< SbSize, Copyable, Base >::as

(

)

Get reference to stored value of specified type.

Template Parameters

T	Type to retrieve (must be exact type, no const/ref)

Returns

Reference to the stored value

Exceptions

std::bad_any_cast

if stored type doesn't match T

as() [2/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T>

const T & Acts::AnyBase< SbSize, Copyable, Base >::as

(

)

const

Get const reference to stored value of specified type.

Template Parameters

T	Type to retrieve (must be exact type, no const/ref)

Returns

Const reference to the stored value

Exceptions

std::bad_any_cast

if stored type doesn't match T

asBase() [1/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename B = Base>
requires (!std::is_void_v<B>)

B * Acts::AnyBase< SbSize, Copyable, Base >::asBase

(

)

Get a pointer to the stored value as Base*, regardless of its concrete type.

Only available when Base is not void.

Returns

Pointer to the stored value upcast to Base*, or nullptr if empty

asBase() [2/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename B = Base>
requires (!std::is_void_v<B>)

const B * Acts::AnyBase< SbSize, Copyable, Base >::asBase

(

)

const

Get a const pointer to the stored value as Base*.

Only available when Base is not void.

Returns

Const pointer to the stored value upcast to Base*, or nullptr if empty

asPtr() [1/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T>

T * Acts::AnyBase< SbSize, Copyable, Base >::asPtr

(

)

Get pointer to stored value of specified type.

Template Parameters

T	Type to retrieve (must be exact type, no const/ref)

Returns

Pointer to the stored value, or nullptr if the type doesn't match or the Any is empty

asPtr() [2/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T>

const T * Acts::AnyBase< SbSize, Copyable, Base >::asPtr

(

)

const

Get const pointer to stored value of specified type.

Template Parameters

T	Type to retrieve (must be exact type, no const/ref)

Returns

Const pointer to the stored value, or nullptr if the type doesn't match or the Any is empty

emplace()

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T, typename... Args>
requires (isStorable<std::decay_t<T>>())

T & Acts::AnyBase< SbSize, Copyable, Base >::emplace

(

Args &&...

args

)

Construct a new value in place, destroying any existing value.

Template Parameters

T	Type to construct
Args	Constructor argument types

Parameters

args	Arguments to forward to T's constructor

Returns

Reference to the newly constructed value

operator bool()

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

Acts::AnyBase< SbSize, Copyable, Base >::operator bool ( ) const

explicit

Check if the AnyBase contains a value.

Returns

True if a value is stored, false if empty

operator*() [1/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename B = Base>
requires (!std::is_void_v<B>)

B & Acts::AnyBase< SbSize, Copyable, Base >::operator*

(

)

Dereference to the stored value as Base&.

Only available when Base is not void.

Returns

Reference to the stored value upcast to Base&

operator*() [2/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename B = Base>
requires (!std::is_void_v<B>)

const B & Acts::AnyBase< SbSize, Copyable, Base >::operator*

(

)

const

Dereference to the stored value as const Base&.

Only available when Base is not void.

Returns

Const reference to the stored value upcast to Base&

operator->() [1/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename B = Base>
requires (!std::is_void_v<B>)

B * Acts::AnyBase< SbSize, Copyable, Base >::operator->

(

)

Member access on the stored value as Base*.

Only available when Base is not void.

Returns

Pointer to the stored value upcast to Base*

operator->() [2/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename B = Base>
requires (!std::is_void_v<B>)

const B * Acts::AnyBase< SbSize, Copyable, Base >::operator->

(

)

const

Member access on the stored value as const Base*.

Only available when Base is not void.

Returns

Const pointer to the stored value upcast to Base*

operator=() [1/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

AnyBase & Acts::AnyBase< SbSize, Copyable, Base >::operator= ( AnyBase< SbSize, Copyable, Base > && other )

noexcept

Move assignment operator.

Parameters

other

The AnyBase to move from

Returns

Reference to this object

operator=() [2/2]

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

AnyBase & Acts::AnyBase< SbSize, Copyable, Base >::operator=

(

const AnyBase< SbSize, Copyable, Base > &

other

)

Copy assignment operator (only when Copyable is true).

Parameters

other

The AnyBase to copy from

Returns

Reference to this object

Note

Not noexcept: copying a heap-allocated value allocates (may throw std::bad_alloc) and the stored type's copy operations may throw.

take()

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

template<typename T>

T Acts::AnyBase< SbSize, Copyable, Base >::take

(

)

Move the stored value out.

Leaves this Any empty.

Template Parameters

T	Type to retrieve (must be exact type, no const/ref)

Returns

The moved-out value

Exceptions

std::bad_any_cast

if stored type doesn't match T or Any is empty

typeInfo()

template<std::size_t SbSize, bool Copyable = true, typename Base = void>

const std::type_info * Acts::AnyBase< SbSize, Copyable, Base >::typeInfo

(

)

const

Type info of the stored value.

Returns nullptr if empty.

Returns

Pointer to the type info of the stored value, or nullptr if empty