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

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

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

		  class Proj1 = ranges::identity, class Proj2 =
	ranges::identity,
		  class Comp = ranges::less<> >
	    requires IndirectStrictWeakOrder<Comp, projected<I1, Proj1>,     (1)
     (ranges TS)
	projected<I2, Proj2>>
	bool lexicographical_compare( I1 first1, S1 last1, I2 first2, S2
	last2,
				      Comp comp = Comp{},

				      Proj1 proj1 = Proj1{}, Proj2 proj2 =
	Proj2{} );
	template< InputRange R1, InputRange R2,

		  class Proj1 = ranges::identity, class Proj2 =
	ranges::identity,
		  class Comp = ranges::less<> >
	    requires IndirectStrictWeakOrder<Comp,
	projected<ranges::iterator_t<R1>, Proj1>,			     (2)
     (ranges TS)

	 projected<ranges::iterator_t<R2>, Proj2>>
	bool lexicographical_compare( R1&& r1, R2&& r2, Comp comp = Comp{},

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

	1) Checks if the first range [first1, last1) is  lexicographically  less
     than the
	second	range [first2, last2). Elements are compared using the given bi-
     nary
	comparison function comp, after being projected with proj1 and proj2 re-
     spectively.
	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.

	Lexicographical  comparison  is  an operation with the following proper-
     ties:

	  * Two ranges are compared element by element.
	  * The first mismatching element defines which range  is  lexicographi-
     cally less or
	    greater than the other.
	  *  If  one  range is a prefix of another, the shorter range is lexico-
     graphically less
	    than the other.
	  * If two ranges have equivalent elements and are of the  same  length,
     then the
	    ranges are lexicographically equal.
	  * An empty range is lexicographically less than any non-empty range.
	  * Two empty ranges are lexicographically equal.

Parameters
	first1, last1 - the first range of elements to examine
	r1	      - the first range of elements to examine
	first2, last2 - the second range of elements to examine
	r2	      - the second range of elements to examine
	comp	      - comparison function 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 first range is lexicographically less than the second.

Complexity
	At  most  2A.min(N1, N2) applications of the comparison operation, where
     N1 = last1 -
	first1 and N2 = last2 - first2.

Possible implementation
	template<InputIterator	I1,  Sentinel<I1>  S1,	InputIterator  I2,  Sen-
     tinel<I2> S2,
		 class Proj1 = ranges::identity, class Proj2 = ranges::identity,
		 class Comp = ranges::less<>>
	    requires  IndirectStrictWeakOrder<Comp,  projected<I1,  Proj1>, pro-
     jected<I2, Proj2>>
	bool lexicographical_compare(I1 first1, S1 last1, I2 first2, S2 last2,
				     Comp comp = Comp{},
				     Proj1  proj1  =  Proj1{},	Proj2  proj2   =
     Proj2{})
	{
	    for  (;  (first1  !=  last1)  && (first2 != last2); (void) ++first1,
     (void) ++first2)
	    {
		if (ranges::invoke(comp, ranges::invoke(proj1, *first1),
					 ranges::invoke(proj2, *first2)))
		    return true;
		if (ranges::invoke(comp, ranges::invoke(proj2, *first2),
					 ranges::invoke(proj1, *first1)))
		    return false;
	    }
	    return (first1 == last1) && (first2 != last2);
	}

Example
	 This section is incomplete
	 Reason: no example

See also
				returns true if one range  is  lexicographically
     less than
	lexicographical_compare another
				(function template)
	equal			determines if two sets of elements are the same
				(function template)

Category:
	  * Todo no example

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