std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>::extract
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Tables
std::flat_multimap
flat_multimap::extract
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.
Contents
[edit] Return value
std::move(c).
[edit] Complexity
Constant.
[edit] Example
Run this code
#include <cassert> #include <flat_map> #include <print> #include <type_traits> #include <utility> #include <vector> int main() { std::flat_multimap <int, double> map{{1, 1.1}, {2, 2.2}, {3, 3.3}}; const auto size{map.size()}; auto c{std::move(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.values), std::vector <double>>); std::println ("keys: {}", c.keys); std::println ("values: {}", c.values); }
Output:
keys: [1, 2, 3] values: [1.1, 2.2, 3.3]