The iteration order of this container is not required to be stable (so, for example,std::equalcannot be used to compare twostd::unordered_multimaps), except that every group of elements whose keys compareequiva
The iteration order of this container is not required to be stable (so, for example,std::equalcannot be used to compare twostd::unordered_multimaps), except that every group of elements whose keys compareequivalent(compare equal withkey_eq()as the comparator) forms a contiguous subrange in t...
Example Defect reports The following behavior-changing defect reports were applied retroactively to previously published C++ standards. DRApplied toBehavior as publishedCorrect behavior LWG 2059C++11there was ambiguity for overload(2)added overload(1) ...
Complexity Amortized constant on average, worst case linear in the size of the container. Example See also emplace_hint constructs elements in-place using a hint (public member function) try_emplace inserts in-place if the key does not exist, does nothing if the key exists ...
Iterator to the element following the last element. Complexity Constant. Example See also begincbegin returns an iterator to the beginning (public member function) endcend (C++11)(C++14) returns an iterator to the end of a container or array (function template)...
Example Run this code #include <iostream>#include <unordered_map>intmain(){std::unordered_multimap<int,char>map={{1,'a'},{1,'b'},{1,'d'},{2,'b'}};autorange=map.equal_range(1);for(autoit=range.first;it!=range.second;++it)std::cout<<it->first<<' '<<it->second<<'\n';...
The behavior is undefined ifget_allocator()!=source.get_allocator(). Parameters Return value (none) Complexity Average case O(N), worst case O(N * size() + N), where N issource.size(). Example See also extract (C++17) extracts nodes from the container ...
Example Run this code #include <iostream> #include <string> #include <utility> #include <unordered_map> // print out a std::pair template<class Os, class U, class V> Os& operator<<(Os& os, const std::pair<U, V>& p) { return os << p.first << ':' << p.second; } // ...
Parameters c-container from which to erase pred-predicate that determines which elements should be erased Complexity Linear. Example See also removeremove_if removes elements satisfying specific criteria (function template)
(since C++20) Erases all elements that satisfy the predicatepredfromc. Equivalent to Parameters Return value The number of erased elements. Complexity Linear. Example See also removeremove_if removes elements satisfying specific criteria (function template)...