std::set::begin, std::set::cbegin

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

span (C++20)

std::set

Member functions

set::set

set::~set

set::operator=

set::get_allocator

Iterators

set::beginset::cbegin (C++11)

set::endset::cend (C++11)

set::rbeginset::crbegin (C++11)

set::rendset::crend (C++11)

Capacity

set::empty

set::size

set::max_size

Modifiers

set::clear

set::insert

set::emplace (C++11)

set::emplace_hint (C++11)

set::erase

set::swap

set::extract (C++17)

set::merge (C++17)

Lookup

set::count

set::find

set::contains (C++20)

set::equal_range

set::lower_bound

set::upper_bound

Observers

set::key_comp

set::value_comp

Deduction guides(C++17)

iterator begin();		(until C++11)
iterator begin() noexcept;		(since C++11)
const_iterator begin() const;		(until C++11)
const_iterator begin() const noexcept;		(since C++11)
const_iterator cbegin() const noexcept;		(since C++11)

Returns an iterator to the first element of the container.

If the container 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.

Example

Run this code

#include <set>
#include <iostream>

int main() {
  std::set<int> set = { 6, 1, 3, 4, 2, 5 };
  for (auto it = set.begin(); it != set.end(); ++it)
    std::cout << *it << "\n";
}

Possible output:

1
2
3
4
5
6

See also

end cend

returns an iterator to the end (public member function)