std::set<Key,Compare,Allocator>::begin, std::set<Key,Compare,Allocator>::cbegin
From cppreference.com
iterator begin(); |
(1) | (noexcept since C++11) |
const_iterator begin() const; |
(2) | (noexcept since C++11) |
const_iterator cbegin() const noexcept; |
(3) | (since C++11) |
Returns an iterator to the first element of the set
.
If the set
is empty, the returned iterator will be equal to end().
Parameters
(none)
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.
libc++ backports cbegin()
to C++98 mode.
Example
Run this code
#include <algorithm> #include <iostream> #include <set> int main() { std::set<int> set{3, 1, 4, 1, 5, 9, 2, 6, 5}; std::for_each(set.cbegin(), set.cend(), [](int x) { std::cout << x << ' '; }); std::cout << '\n'; }
Output:
1 2 3 4 5 6 9
See also
(C++11) |
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) |