(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 |
void clear()noexcept; | (since C++23) (constexpr since C++26) | |
Erases all elements from the container adaptor. After this call,size() returns zero.
Invalidates any references, pointers, and iterators referring to contained elements.
Linear in the size of the container adaptor, i.e., the number of elements.
#include <iostream>#include <string_view>#include <flat_map> void print_info(std::string_view rem,conststd::flat_multimap<int,char>& v){std::cout<< rem<<"{ ";for(constauto&[key, value]: v)std::cout<<'['<< key<<"]:"<< value<<' ';std::cout<<"}\n";std::cout<<"Size="<< v.size()<<'\n';} int main(){std::flat_multimap<int,char> container{{1,'x'},{2,'y'},{3,'z'}}; print_info("Before clear: ", container); container.clear(); print_info("After clear: ", container);}
Output:
Before clear: { [1]:x [2]:y [3]:z }Size=3After clear: { }Size=0| erases elements (public member function)[edit] |
