std:: unordered_map - cppreference.com
Apr 26, 2025 · std::unordered_map is an associative container that contains key-value pairs with unique keys. Search, insertion, and removal of elements have average constant-time complexity.
std:: unordered_set - cppreference.com
Apr 26, 2025 · std::unordered_set is an associative container that contains a set of unique objects of type Key. Search, insertion, and removal have average constant-time complexity.
std::unordered_map<Key,T,Hash,KeyEqual,Allocator>:: find
Dec 4, 2021 · (C++20) unordered_map::equal_range Bucket interface unordered_map::begin(size_type)unordered_map::cbegin(size_type) …
std::unordered_set<Key,Hash,KeyEqual,Allocator>:: erase
Jan 12, 2021 · (C++20) unordered_set::equal_range Bucket interface unordered_set::begin(size_type)unordered_set::cbegin(size_type) …
std::unordered_map<Key,T,Hash,KeyEqual,Allocator>:: count
Dec 4, 2021 · (C++17) Lookup unordered_map::at unordered_map::operator [] unordered_map::count unordered_map::find unordered_map::contains (C++20) unordered_map::equal_range Bucket …
std:: unordered_multimap - cppreference.com
Apr 26, 2025 · std::unordered_multimap is an unordered associative container that supports equivalent keys (an unordered_multimap may contain multiple copies of each key value) and that associates …
std::unordered_map<Key,T,Hash,KeyEqual,Allocator>:: unordered_map
Nov 29, 2021 · Define a const == operator for the class/struct and specialize std::hash// structure in the std namespacestd::unordered_map<std::string>={{(1)"One"}{2"Two"}{3"Three"}};// Option 3: Use …
std::erase_if (std::unordered_set) - cppreference.com
Nov 29, 2021 · std::swap(std::unordered_set) erase_if(std::unordered_set) (C++20) Deduction guides (C++17) [edit] ... Erases all elements that satisfy the predicate pred from c. Equivalent to auto …
Standard library header <unordered_set> (C++11) - Reference
Nov 27, 2023 · Classes unordered_set (C++11) collection of unique keys, hashed by keys (class template) [edit] unordered_multiset (C++11) collection of keys, hashed by keys (class template) [edit]
std::unordered_set<Key,Hash,KeyEqual,Allocator>:: insert
May 9, 2025 · The value_type must be EmplaceConstructible into unordered_set from std::forward<K>(obj). This overload participates in overload resolution only if Hash and KeyEqual are …