::cbegin - cppreference.com (original) (raw)

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().

[edit] Return value

Iterator to the first element.

[edit] Complexity

Constant.

[edit] Example

#include #include int main() { std::flat_map<int, double> map{{4, 4.13}, {9, 9.24}, {1, 1.09}}; for (auto it = map.cbegin(); it != map.cend(); ++it) std::cout << '[' << it->first << "] = " << it->second << '\n'; // Unlike std::map's bidirectional iterators, the std::flat_map iterators // are random-access, so they can be used with the operator[]: auto it = map.cbegin(); assert(it[0] == map[1]); assert(it[1] == map[4]); assert(it[2] == map[9]); }

Output:

[1] = 1.09 [4] = 4.13 [9] = 9.24

[edit] See also

| | returns an iterator to the end (public member function) [edit] | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | returns an iterator to the beginning of a container or array (function template) [edit] |