(C++17) | ||||
| Sequence | ||||
(C++11) | ||||
(C++26) | ||||
(C++26) | ||||
(C++11) | ||||
| Associative | ||||
| Unordered associative | ||||
(C++11) | ||||
(C++11) | ||||
(C++11) | ||||
(C++11) | ||||
| Adaptors | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
| Views | ||||
(C++20) | ||||
(C++23) | ||||
| Tables | ||||
| Iterator invalidation | ||||
| Member function table | ||||
| Non-member function table |
iterator find(const Key& key); | (1) | (since C++23) (constexpr since C++26) |
const_iterator find(const Key& key)const; | (2) | (since C++23) (constexpr since C++26) |
template<class K> iterator find(const K& x); | (3) | (since C++23) (constexpr since C++26) |
template<class K> const_iterator find(const K& x)const; | (4) | (since C++23) (constexpr since C++26) |
Compare istransparent. It allows calling this function without constructing an instance ofKey.Contents |
| key | - | key value of the element to search for |
| x | - | a value of any type that can be transparently compared with a key |
An iterator to the requested element. If no such element is found, past-the-end (seeend()) iterator is returned.
Logarithmic in the size of the container.
#include <iostream>#include <flat_set> struct LightKey{int x;}; struct FatKey{int x;int data[1000];// a heavy blob}; // As detailed above, the container must use std::less<> (or other transparent// Comparator) to access these overloads. This includes standard overloads,// such as comparison between std::string and std::string_view.bool operator<(const FatKey& fk,const LightKey& lk){return fk.x< lk.x;}bool operator<(const LightKey& lk,const FatKey& fk){return lk.x< fk.x;}bool operator<(const FatKey& fk1,const FatKey& fk2){return fk1.x< fk2.x;} int main(){// Simple comparison demo.std::flat_multiset<int> example{1,2,3,4}; if(auto search= example.find(2); search!= example.end())std::cout<<"Found "<<(*search)<<'\n';elsestd::cout<<"Not found\n"; // Transparent comparison demo.std::flat_multiset<FatKey,std::less<>> example2{{1,{}},{2,{}},{3,{}},{4,{}}}; LightKey lk={2};if(auto search= example2.find(lk); search!= example2.end())std::cout<<"Found "<< search->x<<'\n';elsestd::cout<<"Not found\n";}
Output:
Found 2Found 2
| returns the number of elements matching specific key (public member function)[edit] | |
| returns range of elements matching a specific key (public member function)[edit] |
