LiteFX::CovariantIterator< T > Struct Template Reference

Wraps an iterator and returns covariants of type T of the iterated value. More...

#include <containers.hpp>

Public Types
using	value_type = std::remove_cvref_t<T>
	The type of the value that is iterated.
using	iterator_category = std::forward_iterator_tag
	The category of the iterator.
using	difference_type = std::ptrdiff_t
	The type that expresses the difference between two iterators.
using	pointer = std::remove_reference_t<T>*
	The type of a pointer returned by the iterator.

Public Member Functions
	CovariantIterator ()
	Initializes a new iterator instance. Always throws a RuntimeException.
template<typename TIterator >
	CovariantIterator (const TIterator &it)
	Initializes a new iterator instance.
	CovariantIterator (const CovariantIterator &_other)
	Copies another iterator instance.
	CovariantIterator (CovariantIterator &&_other) noexcept=default
	Takes ownership over another iterator instances.
CovariantIterator &	operator= (const CovariantIterator &_other)
	Copies another iterator instance.
CovariantIterator &	operator= (CovariantIterator &&_other)=default
	Takes ownership over another iterator instances.
	~CovariantIterator () noexcept=default
	Releases the iterator.
T	operator* () const
	Returns a reference of the value at the current iterator position.
pointer	operator-> ()
	Returns a pointer to the value at the current iterator position.
CovariantIterator &	operator++ ()
	Increments the iterator position by one.
CovariantIterator	operator++ (int)
	Increments the iterator position by one and returns the previous iterator.
bool	operator== (const CovariantIterator &_other) const
	Checks if two iterators are equal, i.e. they are pointing to the same value.

Detailed Description

template<typename T>
struct LiteFX::CovariantIterator< T >

Wraps an iterator and returns covariants of type T of the iterated value.

This iterator uses type erasure to hide the actual iterated types from the interface. This allows to iterate a range of class instances as a range of base class instances. However, due to the type erasure, each iteration requires a virtual indirection, resulting in slightly lower performance. Limit the use of this iterator to base class interfaces and return a reference to the actual underlying range in child classes instead for most performance.

Template Parameters

T	The type returned by the iterator, that is covariant to the actual iterated type.

See also

Enumerable

Member Typedef Documentation

difference_type

template<typename T >

using LiteFX::CovariantIterator< T >::difference_type = std::ptrdiff_t

The type that expresses the difference between two iterators.

iterator_category

template<typename T >

using LiteFX::CovariantIterator< T >::iterator_category = std::forward_iterator_tag

The category of the iterator.

pointer

template<typename T >

using LiteFX::CovariantIterator< T >::pointer = std::remove_reference_t<T>*

The type of a pointer returned by the iterator.

value_type

template<typename T >

using LiteFX::CovariantIterator< T >::value_type = std::remove_cvref_t<T>

The type of the value that is iterated.

Constructor & Destructor Documentation

CovariantIterator() [1/4]

template<typename T >

LiteFX::CovariantIterator< T >::CovariantIterator ( )

inlineexplicit

Initializes a new iterator instance. Always throws a RuntimeException.

This constructor is only defined to satisfy the std::ranges::range constraint for ranges that return this iterator. Attempting to default-initialize a CovariantInterator will result in a runtime error.

CovariantIterator() [2/4]

template<typename T >

template<typename TIterator >

LiteFX::CovariantIterator< T >::CovariantIterator ( const TIterator & it )

inline

Initializes a new iterator instance.

Template Parameters

TIterator

The type of the iterator that returns the value instances.

Parameters

it	The iterator to wrap within the iterator instance.

CovariantIterator() [3/4]

template<typename T >

LiteFX::CovariantIterator< T >::CovariantIterator ( const CovariantIterator< T > & _other )

inline

Copies another iterator instance.

Parameters

_other

The iterator to copy.

CovariantIterator() [4/4]

template<typename T >

LiteFX::CovariantIterator< T >::CovariantIterator ( CovariantIterator< T > && _other )

inlinedefaultnoexcept

Takes ownership over another iterator instances.

Parameters

_other

The iterator instance to take over.

~CovariantIterator()

template<typename T >

LiteFX::CovariantIterator< T >::~CovariantIterator ( )

defaultnoexcept

Releases the iterator.

Member Function Documentation

operator*()

template<typename T >

T LiteFX::CovariantIterator< T >::operator* ( ) const

inline

Returns a reference of the value at the current iterator position.

Returns

A reference of the value at the current iterator position.

operator++() [1/2]

template<typename T >

CovariantIterator & LiteFX::CovariantIterator< T >::operator++ ( )

inline

Increments the iterator position by one.

Returns

A reference of the current iterator.

operator++() [2/2]

template<typename T >

CovariantIterator LiteFX::CovariantIterator< T >::operator++ ( int )

inline

Increments the iterator position by one and returns the previous iterator.

Returns

A copy of the previous iterator.

operator->()

template<typename T >

pointer LiteFX::CovariantIterator< T >::operator-> ( )

inline

Returns a pointer to the value at the current iterator position.

This operator is only available, if the iterated type is a lvalue reference.

Returns

A pointer to the value at the current iterator position.

operator=() [1/2]

template<typename T >

CovariantIterator & LiteFX::CovariantIterator< T >::operator= ( const CovariantIterator< T > & _other )

inline

Copies another iterator instance.

Parameters

_other

Returns

operator=() [2/2]

template<typename T >

CovariantIterator & LiteFX::CovariantIterator< T >::operator= ( CovariantIterator< T > && _other )

inlinedefault

Takes ownership over another iterator instances.

Parameters

_other

The iterator instance to take over.

Returns

A reference to the current iterator instance.

operator==()

template<typename T >

bool LiteFX::CovariantIterator< T >::operator== ( const CovariantIterator< T > & _other ) const

inline

Checks if two iterators are equal, i.e. they are pointing to the same value.

Parameters

_other

The iterator to check against.

Returns

true, if the iterators are pointing to the same value.