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std::experi...nalIterator(3)  C++ Standard Libary std::experi...nalIterator(3)

NAME
       std::experimental::ranges::BidirectionalIterator	   -   std::experimen-
       tal::ranges::BidirectionalIterator

Synopsis
	  Defined in header <experimental/ranges/iterator>
	  template< class I >

	  concept bool BidirectionalIterator =
	      ForwardIterator<I> &&
	      DerivedFrom<ranges::iterator_category_t<I>,
	  ranges::bidirectional_iterator_tag>				    &&
       (ranges TS)
	      requires(I i) {
		  { --i	} -> Same<I>&;
		  { i--	} -> Same<I>&&;

	      };

	  The  concept	BidirectionalIterator<I>  refines  ForwardIterator  by
       adding the ability
	  to move an iterator backward.

	  A bidirectional iterator r is	said to	be decrementable if  and  only
       if there	exists
	  some s such that ++s == r. All decrementable iterators r shall be in
       the domain of
	  the expressions --r and r--.

	  Let  a and b be decrementable	objects	of type	I. BidirectionalItera-
       tor<I> is
	  satisfied only if:

	    * Pre-decrement yields an  lvalue  that  refers  to	 the  operand:
       std::addressof(--a)
	      == std::addressof(a).
	    *  Post-decrement  yields  the  previous  value of the operand: if
       bool(a == b), then
	      bool(a-- == b).
	    * Post-decrement and pre-decrement perform the  same  modification
       on its operand:
	      If  bool(a == b),	then after evaluating both a-- and --b,	bool(a
       == b) still
	      holds.
	    * Increment	and decrement are inverses of each other:

	    * If a is incrementable and	bool(a == b), then bool(--(++a)	== b).
	    * If bool(a	== b), then bool(++(--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  re-
       quired 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-expres-
       sion is required
	  to be	equality preserving and	stable,	and the	evaluation of the  ex-
       pression	may only
	  modify  its  non-constant  operands. Operands	that are constant must
       not be modified.

http://cppreference.com		  2024.06.10	  std::experi...nalIterator(3)

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