util::BeginEndWrapper< Iterator > Class Template Reference

#include <iterators.h>

Public Types
using	const_iterator = Iterator
using	value_type = typename std::iterator_traits<Iterator>::value_type

Public Member Functions
	BeginEndWrapper ()=default
	If Iterator is default-constructible, an empty range.
	BeginEndWrapper (Iterator begin, Iterator end)
Iterator	begin () const
Iterator	end () const
size_t	size () const
	Available only if Iterator is a random access iterator.
bool	empty () const

Detailed Description

template<typename Iterator>
class util::BeginEndWrapper< Iterator >

This is useful for wrapping iterators of a class that support many different iterations. For instance, on a Graph class, one can write:

BeginEndWrapper<OutgoingArcIterator> Graph::OutgoingArcs(NodeInde node) const { return BeginEndWrapper( OutgoingArcIterator(this, node, /*at_end=‍/false), OutgoingArcIterator(this, node, /*at_end=‍/true)); }

And a client will use it like this:

for (const ArcIndex arc : graph.OutgoingArcs(node)) { ... }

Note

BeginEndWrapper is conceptually a borrowed range as per the C++ standard (std::ranges::borrowed_range): "The concept borrowed_range defines the requirements of a range such that a function can take it by value and return iterators obtained from it without danger of dangling". We cannot static_assert this property though as std::ranges is prohibited in google3.

Definition at line 48 of file iterators.h.

Member Typedef Documentation

const_iterator

template<typename Iterator>

using util::BeginEndWrapper< Iterator >::const_iterator = Iterator

Definition at line 50 of file iterators.h.

value_type

template<typename Iterator>

using util::BeginEndWrapper< Iterator >::value_type = typename std::iterator_traits<Iterator>::value_type

Definition at line 51 of file iterators.h.

Constructor & Destructor Documentation

BeginEndWrapper() [1/2]

template<typename Iterator>

util::BeginEndWrapper< Iterator >::BeginEndWrapper ( )

default

If Iterator is default-constructible, an empty range.

BeginEndWrapper() [2/2]

template<typename Iterator>

util::BeginEndWrapper< Iterator >::BeginEndWrapper ( Iterator begin, Iterator end )

inline

Definition at line 56 of file iterators.h.

Member Function Documentation

begin()

template<typename Iterator>

Iterator util::BeginEndWrapper< Iterator >::begin ( ) const

inline

Definition at line 58 of file iterators.h.

empty()

template<typename Iterator>

bool util::BeginEndWrapper< Iterator >::empty ( ) const

inline

Definition at line 64 of file iterators.h.

end()

template<typename Iterator>

Iterator util::BeginEndWrapper< Iterator >::end ( ) const

inline

Definition at line 59 of file iterators.h.

size()

template<typename Iterator>

size_t util::BeginEndWrapper< Iterator >::size ( ) const

inline

Available only if Iterator is a random access iterator.

Definition at line 62 of file iterators.h.

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

• ortools/graph/iterators.h