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std::flat_map::extract(3)      C++ Standard Libary     std::flat_map::extract(3)

NAME
     std::flat_map::extract - std::flat_map::extract

Synopsis
	containers extract() &&;  (since C++23)

	Extracts adapted containers c. Equivalent to return std::move(c);.

	After this operation *this is empty, even if an exception is thrown.

Parameters
	(none)

Return value
	std::move(c).

Complexity
	Constant.

Example
     // Run this code

      #include <cassert>
      #include <flat_map>
      #include <print>
      #include <type_traits>
      #include <vector>

      int main()
      {
	  std::flat_map<int, double> map{{1, 1.1}, {2, 2.2}, {3, 3.3}};
	  const auto size = map.size();

	  auto c = map.extract();
	  assert(c.keys.size() == size);
	  assert(c.values.size() == size);
	  assert(map.empty());
	  assert(map.keys().empty());
	  assert(map.values().empty());

	  // The default keys and values containers are std::vector:
	  static_assert(std::is_same_v<decltype(c.keys), std::vector<int>>);
	  static_assert(std::is_same_v<decltype(c.value), std::vector<int>>);

	  std::println("keys: {}", c.keys);
	  std::println("values: {}", c.values);
      }

Output:
      keys: [1, 2, 3]
      values: [1.1, 2.2, 3.3]

See also
	replace replaces the underlying containers
		(public member function)

http://cppreference.com 	   2024.06.10	       std::flat_map::extract(3)
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