C++ concepts: ForwardIterator

 

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C++ concepts

Basic
DefaultConstructible CopyAssignable CopyConstructible	MoveAssignable (C++11) MoveConstructible (C++11) Destructible
Library-Wide
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Iterator OutputIterator InputIterator	ForwardIterator BidirectionalIterator RandomAccessIterator
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FormattedInputFunction UnformattedInputFunction	FormattedOutputFunction UnformattedOutputFunction
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Other
CharTraits pos_type off_type Clock (C++11)	UnaryTypeTrait (C++11) BinaryTypeTrait (C++11) TransformationTrait (C++11) TrivialClock (C++11)

 

A ForwardIterator is an Iterator that can read data from the pointed-to element.

Unlike an InputIterator, it guarantees validity when used in multipass algorithms.

Requirements

• InputIterator
• DefaultConstructible
• a == b implies ++a == ++b

In addition to the above requirements, for a type It to be an Forwardterator, an instance i of It must:

Expression	Return	Equivalent expression	Notes
++i	const It&		After this, copies of i are still valid
i++		value_type temp = *i; ++i; return temp;
*i++	reference

A mutable ForwardIterator is a ForwardIterator that additionally satisfies the OutputIterator requirements.

See also

• Iterator library