regina::ChildIterator< const_ > Class Template Reference

A forward iterator for iterating through all immediate children of a given packet. More...

#include <packet/packet.h>

Public Types
using	value_type = typename std::conditional< const_, const Packet, Packet >::type
	Indicates what the iterator points to. More...
using	iterator_category = std::forward_iterator_tag
	Declares this to be a forward iterator type. More...
using	difference_type = ptrdiff_t
	The type obtained by subtracting iterators. More...
using	pointer = value_type *
	A pointer to value_type. More...
using	reference = value_type &
	A reference to value_type. More...

Public Member Functions
	ChildIterator ()=default
	Creates a past-the-end iterator. More...
	ChildIterator (const ChildIterator &)=default
	Default copy constructor. More...
	ChildIterator (std::shared_ptr< value_type > current)
	Creates a new iterator pointing to the given child packet. More...
ChildIterator &	operator= (const ChildIterator &)=default
	Default copy assignment operator. More...
bool	operator== (const ChildIterator &rhs) const
	Tests whether this and the given iterator are equal. More...
bool	operator!= (const ChildIterator &rhs) const
	Tests whether this and the given iterator are different. More...
ChildIterator &	operator++ ()
	Preincrement operator. More...
ChildIterator	operator++ (int)
	Postincrement operator. More...
value_type &	operator* () const
	Returns the packet that this iterator is currently pointing to. More...
	operator bool () const
	Identifies whether this iterator is dereferencable. More...

Detailed Description

template<bool const_>
class regina::ChildIterator< const_ >

A forward iterator for iterating through all immediate children of a given packet.

Each iterator will hold a std::shared_ptr to the packet whose children it is iterating over. This guarantees that the packet will not be destroyed mid-iteration, but it also means that you must ensure that you dispose of your iterators once you are finished with them.

Template Parameters

const_

Indicates whether this iterator should offer const or non-const access to the child packets.

Python

Instead of the C++ interface described here, in Python the classes PacketChildren and ChildIterator together implement the Python iterable/iterator interface. The class PacketChildren has just the single function iter(), which returns a ChildIterator; then ChildIterator implements next(), which either returns the next child packet in the iteration or else throws a StopException if there are no more children to return. All iteration in Python is non-const (i.e., Python exclusively uses the classes where const_ is false).

Member Typedef Documentation

difference_type

template<bool const_>

using regina::ChildIterator< const_ >::difference_type = ptrdiff_t

The type obtained by subtracting iterators.

iterator_category

template<bool const_>

using regina::ChildIterator< const_ >::iterator_category = std::forward_iterator_tag

Declares this to be a forward iterator type.

pointer

template<bool const_>

using regina::ChildIterator< const_ >::pointer = value_type*

A pointer to value_type.

reference

template<bool const_>

using regina::ChildIterator< const_ >::reference = value_type&

A reference to value_type.

value_type

template<bool const_>

using regina::ChildIterator< const_ >::value_type = typename std::conditional<const_, const Packet, Packet>::type

Indicates what the iterator points to.

This is either Packet or const Packet, according to the template argument const_.

Constructor & Destructor Documentation

ChildIterator() [1/3]

template<bool const_>

regina::ChildIterator< const_ >::ChildIterator ( )

default

Creates a past-the-end iterator.

Python

Not present. The only way to create a ChildIterator is via Packet::children().

ChildIterator() [2/3]

template<bool const_>

regina::ChildIterator< const_ >::ChildIterator ( const ChildIterator< const_ > &  )

default

Default copy constructor.

Python

Not present. The only way to create a ChildIterator is via Packet::children().

ChildIterator() [3/3]

template<bool const_>

regina::ChildIterator< const_ >::ChildIterator ( std::shared_ptr< value_type >  current )

inline

Creates a new iterator pointing to the given child packet.

Python

Not present. The only way to create a ChildIterator is via Packet::children().

Parameters

current

the child packet that the new iterator should point to, or null if the new iterator should be past-the-end.

Member Function Documentation

operator bool()

template<bool const_>

regina::ChildIterator< const_ >::operator bool

inline

Identifies whether this iterator is dereferencable.

Python

Not present; instead this class implements next(), which either returns the current child packet and increments the iterator, or else throws a StopIteration exception if the iterator is not dereferencable.

Returns

true if and only if this is dereferencable (i.e., not past-the-end).

operator!=()

template<bool const_>

bool regina::ChildIterator< const_ >::operator!= ( const ChildIterator< const_ > &  rhs ) const

inline

Tests whether this and the given iterator are different.

Returns

true if and only if the two iterators are different.

operator*()

template<bool const_>

ChildIterator< const_ >::value_type & regina::ChildIterator< const_ >::operator*

inline

Returns the packet that this iterator is currently pointing to.

Python

Not present; instead this class implements next(), which either returns the current child packet and increments the iterator, or else throws a StopIteration exception if the iterator is past-the-end.

Returns

the current packet.

operator++() [1/2]

template<bool const_>

ChildIterator< const_ > & regina::ChildIterator< const_ >::operator++

inline

Preincrement operator.

Python

Not present; instead this class implements next(), which either returns the current child packet and increments the iterator, or else throws a StopIteration exception if the iterator is past-the-end.

Returns

a reference to this iterator.

operator++() [2/2]

template<bool const_>

ChildIterator< const_ > regina::ChildIterator< const_ >::operator++ ( int  )

inline

Postincrement operator.

Python

Not present; instead this class implements next(), which either returns the current child packet and increments the iterator, or else throws a StopIteration exception if the iterator is past-the-end.

Returns

a a copy of this iterator before it was incremented.

operator=()

template<bool const_>

ChildIterator & regina::ChildIterator< const_ >::operator= ( const ChildIterator< const_ > &  )

default

Default copy assignment operator.

operator==()

template<bool const_>

bool regina::ChildIterator< const_ >::operator== ( const ChildIterator< const_ > &  rhs ) const

inline

Tests whether this and the given iterator are equal.

Returns

true if and only if the two iterators are equal.

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

• packet/packet.h