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deductiongu...forstd::list(3)  C++ Standard Libary deductiongu...forstd::list(3)

NAME
     deductionguidesforstd::list - deductionguidesforstd::list

Synopsis
	Defined in header <list>
	template< class InputIt,

		  class Alloc = std::allocator<
		      typename std::iterator_traits<InputIt>::value_type>
	>								     (1)
     (since C++17)
	list( InputIt, InputIt, Alloc = Alloc() )

	    -> list<typename std::iterator_traits<InputIt>::value_type,
	Alloc>;
	template< ranges::input_range R,

		  class Alloc = std::allocator<ranges::range_value_t<R>>  >  (2)
     (since C++23)
	list( std::from_range_t, R&&, Alloc = Alloc() )

	    -> list<ranges::range_value_t<R>, Alloc>;

	1)  This deduction guide is provided for list to allow deduction from an
     iterator
	range. This overload participates in overload resolution only if InputIt
     satisfies
	LegacyInputIterator and Alloc satisfies Allocator.
	2) This deduction guide is provided for list to allow deduction from a
	std::from_range_t tag and an input_range.

	Note: the extent to which the library determines that a  type  does  not
     satisfy
	LegacyInputIterator  is  unspecified,  except that as a minimum integral
     types do not
	qualify as input iterators. Likewise, the extent to which it  determines
     that a type
	does  not satisfy Allocator is unspecified, except that as a minimum the
     member type
	Alloc::value_type must exist and the expression
	std::declval<Alloc&>().allocate(std::size_t{}) must be well-formed  when
     treated as
	an unevaluated operand.

Notes
	    Feature-test macro	     Value    Std		    Feature
	__cpp_lib_containers_ranges  202202L  (C++23)  Ranges-aware construction
     and insertion;
						    overload (2)

Example
     // Run this code

      #include <list>
      #include <vector>

      int main()
      {
	  std::vector<int> v = {1, 2, 3, 4};

	  // uses explicit deduction guide to deduce std::list<int>
	  std::list x(v.begin(), v.end());

	  // deduces std::list<std::vector<int>::iterator>
	  // first phase of overload resolution for list-initialization  selects
     the candidate
	  //  synthesized from the initializer-list constructor; second phase is
     not performed
	  // and deduction guide has no effect
	  std::list y{v.begin(), v.end()};
      }

http://cppreference.com 	   2024.06.10	   deductiongu...forstd::list(3)
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