C++ concepts: InputIterator

 

C++

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C++ concepts

Basic
DefaultConstructible CopyAssignable CopyConstructible	MoveAssignable (C++11) MoveConstructible (C++11) Destructible
Library-Wide
EqualityComparable LessThanComparable Swappable (C++11) ValueSwappable (C++11)	NullablePointer (C++11) Hash (C++11) Allocator
Container
Container SequenceContainer ReversibleContainer	AssociativeContainer AllocatorAwareContainer UnorderedAssociativeContainer (C++11)
Container Elements
CopyInsertable (C++11) MoveInsertable (C++11)	EmplaceConstructible (C++11)
Iterator
Iterator OutputIterator InputIterator	ForwardIterator BidirectionalIterator RandomAccessIterator
Stream I/O
FormattedInputFunction UnformattedInputFunction	FormattedOutputFunction UnformattedOutputFunction
Random Numbers
SeedSequence (C++11) RandomNumberEngine (C++11)	RandomNumberDistribution (C++11) UniformRandomNumberGenerator (C++11) RandomNumberEngineAdaptor (C++11)
Concurrency
BasicLockable (C++11) Lockable (C++11) TimedLockable (C++11)	Mutex (C++11) TimedMutex (C++11) SharedMutex (C++14)
Other
CharTraits pos_type off_type Clock (C++11) BitmaskType	UnaryTypeTrait (C++11) BinaryTypeTrait (C++11) TransformationTrait (C++11) TrivialClock (C++11) LiteralType (C++11)

 

An InputIterator is an Iterator that can read from the pointed-to element. InputIterators only guarantee validity for single pass algorithms: once an InputIterator i has been incremented, all copies of its previous value may be invalidated.

Requirements

• Iterator
• EqualityComparable

In addition to the above requirements, for a type It to be an InputIterator, instances i and j of It must:

Expression	Return	Equivalent expression	Notes
i != j	contextually convertible to bool	!(i == j)	Precondition: (i, j) is in the domain of ==.
*i	convertible to value_type	If i == j and (i, j) is in the domain of == then this is equivalent to *j.	Precondition: i is dereferenceable. The expression (void)*i, *i is equivalent to *i.
i->m		(*i).m	Precondition: i is dereferenceable.
++i	It&		Precondition: i is dereferenceable. Postcondition: i is dereferenceable or i is past-the-end. Postcondition: Any copies of the previous value of i are no longer required to be either dereferenceable or to be in the domain of ==.
(void)i++		(void)++i
*i++	convertible to value_type	value_type x = *i; ++i; return x;

See also

• Iterator library