From cppreference.com
iteratorbegin()noexcept; (1) (since C++23)const_iteratorbegin()constnoexcept; (2) (since C++23)const_iteratorcbegin()constnoexcept; (3) (since C++23)Returns an iterator to the first element of the flat_set.
If the flat_set is empty, the returned iterator will be equal to end().
Return value
Iterator to the first element.
Complexity
Constant.
Notes
Because both iterator and const_iterator are constant iterators (and may in fact be the same type), it is not possible to mutate the elements of the container through an iterator returned by any of these member functions.
Example
Run this code
#include<algorithm>#include<flat_set>#include<iostream>intmain(){std::flat_set<int>set{3,1,4,1,5,9,2,6,5};std::for_each(set.cbegin(),set.cend(),[](intx){std::cout<<x<<' ';});std::cout<<'\n';}Output:
1 2 3 4 5 6 9 See also
returns an iterator to the end
(public member function)
(C++11)(C++14)
returns an iterator to the beginning of a container or array
(function template)