std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>::begin, std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>::cbegin
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Tables
std::flat_multimap
flat_multimap::beginflat_multimap::cbegin
iterator begin() noexcept;
(1)
(since C++23) (constexpr since C++26)
const_iterator begin() const noexcept;
(2)
(since C++23) (constexpr since C++26)
const_iterator cbegin() const noexcept;
(3)
(since C++23) (constexpr since C++26)
Returns an iterator to the first element of *this.
If *this is empty, the returned iterator will be equal to end().
Contents
[edit] Return value
Iterator to the first element.
[edit] Complexity
Constant.
[edit] Example
Run this code
#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); }
Output:
[1] = 19 [4] = 13 [4] = 42 [9] = 94
[edit] See also
(C++11)(C++14)
(function template) [edit]