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std::ranges::in_out_result(3)  C++ Standard Libary std::ranges::in_out_result(3)

NAME
     std::ranges::in_out_result - std::ranges::in_out_result

Synopsis
	Defined in header <algorithm>
	template< class I, class O >   (since C++20)
	struct in_out_result;

	ranges::in_out_result  is  a class template that provides a way to store
     two iterators
	as a single unit.

	This class template has no base classes or declared members  other  than
     those shown
	below. Thus it is suitable for use with structured bindings.

	All  special  member functions of this class template are implicitly de-
     clared, which
	makes specializations be aggregate classes, and propagate triviality,
	potentially-throwing-ness, and constexpr-ness  of  corresponding  opera-
     tions on data
	members.

Template parameters
	I, O - the types of the objects that the ranges::in_out_result stores.

	Data members

	Member name Definition
	in	    a value (that is supposed to be an iterator) of type I.
		    (public member object)
	out	    a value (that is supposed to be an iterator) of type O.
		    (public member object)

	All these members are declared with [[no_unique_address]] attribute.

Member functions
     std::ranges::in_out_result::operator in_out_result<I2, O2>

	template<class I2, class O2>

	requires  std::convertible_to<const I&, I2> && std::convertible_to<const
     O&, O2> (1)

	constexpr operator in_out_result<I2, O2>() const &;
	template<class I2, class O2>

	requires  std::convertible_to<I,  I2>  &&   std::convertible_to<O,   O2>
     (2)

	constexpr operator in_out_result<I2, O2>() &&;

	Converts  *this  to  the result by constructing every data member of the
     result from
	the corresponding member of *this.

	1) Equivalent to return {in, out};.
	2) Equivalent to return {std::move(in), std::move(out)};.

Standard library
	The following standard library functions  use  ranges::in_out_result  as
     the return
	type:

	      Algorithm functions
	ranges::copy
	ranges::copy_if 	      copies  a range of elements to a new loca-
     tion
	(C++20) 		     (niebloid)
	(C++20)
	ranges::copy_n		     copies a number of elements to a new  loca-
     tion
	(C++20) 		     (niebloid)
	ranges::copy_backward	     copies a range of elements in backwards or-
     der
	(C++20) 		     (niebloid)
	ranges::move		     moves a range of elements to a new location
	(C++20) 		     (niebloid)
	ranges::move_backward	     moves a range of elements to a new location
     in
	(C++20) 		     backwards order
				     (niebloid)
	ranges::transform	     applies a function to a range of elements
	(C++20) 		     (niebloid)
	ranges::replace_copy	     copies a range, replacing elements satisfy-
     ing specific
	ranges::replace_copy_if      criteria with another value
	(C++20) 		     (niebloid)
	(C++20)
	ranges::remove_copy	      copies  a range of elements omitting those
     that satisfy
	ranges::remove_copy_if	     specific criteria
	(C++20) 		     (niebloid)
	(C++20)
	ranges::unique_copy	     creates a copy of some  range  of	elements
     that contains
	(C++20) 		     no consecutive duplicates
				     (niebloid)
	ranges::reverse_copy	     creates a copy of a range that is reversed
	(C++20) 		     (niebloid)
	ranges::rotate_copy	     copies and rotate a range of elements
	(C++20) 		     (niebloid)
	ranges::partial_sort_copy     copies and partially sorts a range of ele-
     ments
	(C++20) 		     (niebloid)
	ranges::set_difference	     computes the difference between two sets
	(C++20) 		     (niebloid)
	      Memory functions
	ranges::uninitialized_copy   copies a range of objects to an  uninitial-
     ized area of
	(C++20) 		     memory
				     (niebloid)
	ranges::uninitialized_copy_n copies a number of objects to an uninitial-
     ized area of
	(C++20) 		     memory
				     (niebloid)
	ranges::uninitialized_move    moves  a range of objects to an uninitial-
     ized area of
	(C++20) 		     memory
				     (niebloid)
	ranges::uninitialized_move_n moves a number of objects to an  uninitial-
     ized area of
	(C++20) 		     memory
				     (niebloid)

Synopsis
      namespace std::ranges
      {
	  template<class I, class O>
	  struct in_out_result
	  {
	      [[no_unique_address]] I in;
	      [[no_unique_address]] O out;

	      template<class I2, class O2>
	      requires	 std::convertible_to<const   I&,  I2>  &&  std::convert-
     ible_to<const O&, O2>
	      constexpr operator in_out_result<I2, O2>() const &
	      {
		  return {in, out};
	      }

	      template<class I2, class O2>
	      requires std::convertible_to<I, I2> && std::convertible_to<O, O2>
	      constexpr operator in_out_result<I2, O2>() &&
	      {
		  return {std::move(in), std::move(out)};
	      }
	  };
      }

Notes
	Each standard library algorithm that uses this family  of  return  types
     declares a new
	alias type, e.g. using merge_result = in_in_out_result<I1, I2, O>;.

	The  names for such aliases are formed by adding the suffix "_result" to
     the
	algorithm's name. So, the return type of std::ranges::merge can be named
     as
	std::ranges::merge_result.

	Unlike std::pair and std::tuple, this class template has data members of
     meaningful
	names.

Example
     // Run this code

      #include <algorithm>
      #include <array>
      #include <cctype>
      #include <iostream>
      #include <ranges>

      int main()
      {
	  constexpr char in[] = "transform" "\n";
	  std::array<char, sizeof(in)> out;

	  const auto result = std::ranges::transform(in, out.begin(),
	      [](char c) { return std::toupper(c); });

	  auto print = [](char c) { std::cout << c; };
	  std::ranges::for_each(std::cbegin(in), result.in, print);
	  std::ranges::for_each(out.cbegin(), result.out, print);
      }

Output:
      transform
      TRANSFORM

See also
	pair	implements binary tuple, i.e. a pair of values
		(class template)
	tuple	implements fixed size container, which holds elements of  possi-
     bly different
	(C++11) types
		(class template)

http://cppreference.com 	   2024.06.10	   std::ranges::in_out_result(3)
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