std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>:: begin, std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>:: cbegin

Returns an iterator to the first element of the flat_multimap .

If the flat_multimap is empty, the returned iterator will be equal to end() .

Parameters

(none)

Return value

Iterator to the first element.

Complexity

Constant.

Example

#include <iostream>
#include <flat_map>
 
int main()
{
    std::flat_multimap<int, int> map{{4, 13}, {9, 94}, {1, 19}, {4, 42}};
 
    for (auto it = map.cbegin(); it != map.cend(); ++it)
        std::cout << '[' << it->first << "] = " << it->second << '\n';
 
    // Unlike std::multimap's bidirectional iterators, the std::flat_multimap
    // iterators are random-access, so they can be used with the operator[]:
    auto it = map.cbegin();
    assert(it[1] == 19);
    assert(it[4] == 13);
    assert(it[4] == 42);
    assert(it[9] == 94);
}

[1] = 19
[4] = 13
[4] = 42
[9] = 94

See also