std::experimental::ranges::Incrementable

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Technical Specifications

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Readable Writable WeaklyIncrementable Incrementable	Iterator Sentinel SizedSentinel	InputIterator ForwardIterator BidirectionalIterator RandomAccessIterator	OutputIterator
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IndirectUnaryInvocableIndirectRegularUnaryInvocable	IndirectUnaryPredicate	IndirectRelation	IndirectStrictWeakOrder
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IndirectlyMovable IndirectlyMovableStorable	IndirectlyCopyable IndirectlyCopyableStorable	IndirectlySwappable IndirectlyComparable	Permutable Mergeable Sortable
Concept utilities
indirect_result_of	projected
Iterator utilities and operations
iter_move iter_swap	advance distance	next prev
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difference_type value_type reference_t rvalue_reference_t iter_common_reference_t iterator_category	input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tag	ranges::iterator_traits std::iterator_traits<InputIterator>std::iterator_traits<OutputIterator>
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reverse_iterator move_iterator move_sentinel	back_insert_iterator front_insert_iterator insert_iterator	common_iterator counted_iterator default_sentinel	danglingsafe_iterator_t unreachable
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istream_iterator	ostream_iterator	istreambuf_iterator	ostreambuf_iterator

Defined in header <experimental/ranges/iterator>
template <class I> concept bool Incrementable = Regular<I> && WeaklyIncrementable<I> && requires(I i) { { i++ } -> Same<I>&&; };		(ranges TS)

The concept Incrementable<I> specifies the requirements on a type that can be incremented (with the pre- and post-increment operators). The increment operations (including those required by WeaklyIncrementable) are required to be equality-preserving, and the type is required to be EqualityComparable.

Let a and b be incrementable objects of type I. Incrementable<I> is satisfied only if:

• If bool(a == b) then bool(a++ == b).
• If bool(a == b) then bool(void(a++), a) == ++b).

Equality preservation

An expression is equality preserving if it results in equal outputs given equal inputs.

• The inputs to an expression consist of its operands.
• The outputs of an expression consist of its result and all operands modified by the expression (if any).

Every expression required to be equality preserving is further required to be stable: two evaluations of such an expression with the same input objects must have equal outputs absent any explicit intervening modification of those input objects.

Unless noted otherwise, every expression used in a requires-expression is required to be equality preserving and stable, and the evaluation of the expression may only modify its non-constant operands. Operands that are constant must not be modified.

Notes

The requirement that a equals b implies ++a equals ++b allows the use of multi-pass algorithms with Incrementable types.