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std::ranges..._view::begin(3) C++ Standard Libarystd::ranges..._view::begin(3)

NAME
       std::ranges::drop_view::begin - std::ranges::drop_view::begin

Synopsis
	  constexpr auto begin()

	      requires	(!(__SimpleView<V> &&			    (1)	(since
       C++20)
			   ranges::random_access_range<const V>	&&

			   ranges::sized_range<const V>));
	  constexpr auto begin() const

	      requires ranges::random_access_range<const V> &&	   (2)	(since
       C++20)

		       ranges::sized_range<const V>;

	  Returns  an iterator to the first element of the drop_view, that is,
       an iterator to
	  the N^th element of the underlying view, or to the end of the	under-
       lying view if it
	  has less than	N elements.

	  If V is not a	random_access_range or a sized_range, in order to pro-
       vide the
	  amortized constant time complexity required by  the  range  concept,
       the overload (1)
	  caches  the result within the	drop_view object for use on subsequent
       calls.

Parameters
	  (none)

Return value
	  ranges::next(ranges::begin(base_),   count_,	  ranges::end(base_)),
       where base_ is the
	  underlying view, and count_ is the number of elements	to skip.

Example
       // Run this code

	#include <array>
	#include <concepts>
	#include <iostream>
	#include <iterator>
	#include <ranges>

	void println(std::ranges::range	auto const& range)
	{
	    for	(auto const& elem : range)
		std::cout << elem;
	    std::cout << '\n';
	}

	int main()
	{
	    std::array	hi{'H',	 'e',  'l', 'l', 'o', ',', ' ',	'C', '+', '+',
       '2', '0', '!'};
	    println(hi);

	    const auto pos =  std::distance(hi.begin(),	 std::ranges::find(hi,
       'C'));
	    auto cxx = std::ranges::drop_view{hi, pos};
	    std::cout << "*drop_view::begin() == '" << *cxx.begin() << "'\n";
	//   *cxx.begin()  =  'c'; // undefined: 'views' are to	be used	as ob-
       servers
	    println(cxx);
	}

Output:
	Hello, C++20!
	*drop_view::begin() == 'C'
	C++20!

	  Defect reports

	  The following	behavior-changing defect reports were applied retroac-
       tively to
	  previously published C++ standards.

	     DR	   Applied to	     Behavior as  published		  Cor-
       rect behavior
	  LWG  3482  C++20	the const overload can be called     the const
       overload	requires
			      with unsized ranges		   sized_range

See also
	  end		returns	an iterator or a sentinel to the end
	  (C++20)	(public	member function)
	  ranges::begin	returns	an iterator to the beginning of	a range
	  (C++20)	(customization point object)
	  ranges::end	returns	a sentinel indicating the end of a range
	  (C++20)	(customization point object)

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

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