(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 |
std::unordered_multimap| Member types | ||||||
| Member functions | ||||||
| Non-member functions | ||||||
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| Deduction guides(C++17) | ||||||
template<class H2,class P2> void merge(std::unordered_map<Key, T, H2, P2, Allocator>& source); | (1) | (since C++17) (constexpr since C++26) |
template<class H2,class P2> void merge(std::unordered_map<Key, T, H2, P2, Allocator>&& source); | (2) | (since C++17) (constexpr since C++26) |
template<class H2,class P2> void merge(std::unordered_multimap<Key, T, H2, P2, Allocator>& source); | (3) | (since C++17) (constexpr since C++26) |
template<class H2,class P2> void merge(std::unordered_multimap<Key, T, H2, P2, Allocator>&& source); | (4) | (since C++17) (constexpr since C++26) |
Attempts to extract (“splice”) each element insource and insert it into*this using the hash function and key equality predicate of*this.
Ifget_allocator()== source.get_allocator() isfalse, the behavior is undefined.
No elements are copied or moved, only the internal pointers of the container nodes are repointed. All pointers and references to the transferred elements remain valid, but now refer into*this, not intosource.Iterators referring to the transferred elements and all iterators referring to*this are invalidated.
Contents |
| source | - | compatible container to transfer the nodes from |
Given\(\scriptsize S\)S assize() and\(\scriptsize N\)N assource.size():
#include <iostream>#include <string>#include <unordered_map>#include <utility> // print out a std::pairtemplate<class Os,class U,class V>Os& operator<<(Os& os,conststd::pair<U,V>& p){return os<<'{'<< p.first<<", "<< p.second<<'}';} // print out an associative containertemplate<class Os,class K,class V>Os& operator<<(Os& os,conststd::unordered_multimap<K, V>& v){ os<<'['<< v.size()<<"] {";bool o{};for(constauto& e: v) os<<(o?", ":(o=1,""))<< e;return os<<"}\n";} int main(){std::unordered_multimap<std::string,int> p{{"C",3},{"B",2},{"A",1},{"A",0}}, q{{"E",6},{"E",7},{"D",5},{"A",4}}; std::cout<<"p: "<< p<<"q: "<< q; p.merge(q); std::cout<<"p.merge(q);\n"<<"p: "<< p<<"q: "<< q;}
Possible output:
p: [4] {{A, 1}, {A, 0}, {B, 2}, {C, 3}}q: [4] {{A, 4}, {D, 5}, {E, 6}, {E, 7}}p.merge(q);p: [8] {{E, 6}, {E, 7}, {C, 3}, {A, 1}, {A, 0}, {A, 4}, {D, 5}, {B, 2}}q: [0] {}(C++17) | extracts nodes from the container (public member function)[edit] |
| inserts elementsor nodes(since C++17) (public member function)[edit] |
