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

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

Synopsis
	Defined in header <experimental/ranges/algorithm>
	template< ForwardIterator I1, Sentinel<I1> S1, ForwardIterator I2,
	Sentinel<I2> S2,

		  class Pred = ranges::equal_to<>,
		  class Proj1 = ranges::identity, class Proj2 =
	ranges::identity >						     (1)
     (ranges TS)
	    requires IndirectlyComparable<I1, I2, Pred, Proj1, Proj2>
	bool is_permutation( I1 first1, S1 last1, I2 first2, S2 last2, Pred
	pred = Pred{},

			     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}
	);
	template< ForwardRange R1, ForwardRange R2, class Pred =
	ranges::equal_to<>,

		  class Proj1 = ranges::identity, class Proj2 =
	ranges::identity >
	    requires  IndirectlyComparable<ranges::iterator_t<R1>,	     (2)
     (ranges TS)
	ranges::iterator_t<R2>,
					  Pred, Proj1, Proj2>
	bool is_permutation( R1&& r1, R2&& r2, Pred pred = Pred{},

			     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}
	);
	template< ForwardIterator I1, Sentinel<I1> S1, class I2,

		  class Pred = ranges::equal_to<>,
		  class Proj1 = ranges::identity, class Proj2 =
	ranges::identity >
	    requires   ForwardIterator<std::decay_t<I2>>   &&	!Range<I2>    &&
     (ranges TS)
		     IndirectlyComparable<I1,  std::decay_t<I2>, Pred,	     (3)
     (deprecated)
	Proj1, Proj2>
	bool is_permutation( I1 first1, S1 last1, I2&& first2_, Pred pred =
	Pred{},

			     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}
	);
	template< ForwardRange R1, class I2, class Pred =
	ranges::equal_to<>,

		  class Proj1 = ranges::identity, class Proj2 =
	ranges::identity >
	    requires ForwardIterator<std::decay_t<I2>> && !Range<I2> &&      (4)
     (ranges TS)
		     IndirectlyComparable<ranges::iterator_t<R1>,
     (deprecated)
	std::decay_t<I2>, Pred, Proj1, Proj2>
	bool is_permutation( R1&& r1, I2&& first2_, Pred pred = Pred{},

			     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{}
	);

	1) Returns true if there exists a permutation of the elements in range
	[first1, last1) that makes the range equal to [first2, last2), and false
     otherwise.
	2) Same as (1), but uses r1 as the first source range and r2 as the sec-
     ond source
	range,	as  if	using  ranges::begin(r1)  as  first1, ranges::end(r1) as
     last1,
	ranges::begin(r2) as first2, and ranges::end(r2) as last2.
	3) Same as (1), except that first2 is defined as if by	std::decay_t<I2>
     first2 =
	std::forward<I2>(first2_); and last2 is first2 + (last1 - first1).
	4)  Same  as  (3),  but  uses  r1 as the first source range, as if using
     ranges::begin(r1)
	as first1 and ranges::end(r1) as last1.

	Two ranges are considered equal if they have the same number of elements
     and, for
	every iterator i in the range [first1, last1), ranges::invoke(pred,
	ranges::invoke(proj1,  *i),  ranges::invoke(proj2,  *(first2  +   (i   -
     first1)))) is true.

	Notwithstanding  the  declarations depicted above, the actual number and
     order of
	template parameters for algorithm declarations is unspecified. Thus,  if
     explicit
	template  arguments  are  used when calling an algorithm, the program is
     probably
	non-portable.

Parameters
	first1, last1 - the first range of the elements
	r1	      - the first range of the elements
	first2, last2 - the second range of the elements
	r2	      - the second range of the elements
	first2_       - the beginning of the second range of the elements
	pred	      - predicate to apply to the projected elements
	proj1	      - projection to apply to the elements in the first range
	proj2	      - projection to apply to the elements in the second range

Return value
	true if the range [first1, last1) is a permutation of the range [first2,
     last2).

Complexity
	At most O(N^2) applications of the predicate and each projection, or ex-
     actly N if
	the sequences are already equal, where N = last1 - first1.

	However if SizedSentinel<S1, I1> && SizedSentinel<S2, I2>  is  satisfied
     and last1 -
	first1	!=  last2 - first2, no applications of the predicate and projec-
     tions are made.

Example
	 This section is incomplete
	 Reason: no example

See also
	is_permutation	 determines if a sequence is a	permutation  of  another
     sequence
	(C++11) 	 (function template)
			 generates the next greater lexicographic permutation of
     a range of
	next_permutation elements
			 (function template)
			 generates the next smaller lexicographic permutation of
     a range of
	prev_permutation elements
			 (function template)

Category:
	  * Todo no example

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