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

reverse_iterator rbegin();	(1)	(noexcept since C++11) (constexpr since C++26)
const_reverse_iterator rbegin() const;	(2)	(noexcept since C++11) (constexpr since C++26)
const_reverse_iterator crbegin() const noexcept;	(3)	(since C++11) (constexpr since C++26)

Returns a reverse iterator to the first element of the reversed *this. It corresponds to the last element of the non-reversed *this.

If *this is empty, the returned iterator is equal to rend().

[edit] Return value

Reverse iterator to the first element.

[edit] Complexity

Constant.

[edit] Notes

The underlying iterator of the returned reverse iterator is the end iterator. Hence the returned iterator is invalidated if and when the end iterator is invalidated.

libc++ backports crbegin() to C++98 mode.

[edit] Example

#include #include #include #include int main() { std::multimap<std::string, int> map { {"█", 1}, {"▒", 5}, {"░", 3}, {"▓", 7}, {"▓", 8}, {"░", 4}, {"▒", 6}, {"█", 2} }; std::cout << "Print out in reverse order using const reverse iterators:\n"; std::for_each(map.crbegin(), map.crend(), <const std::string, int> const& e) { std::cout << "{ "" << e.first << "", " << e.second << " };\n"; }); map.rbegin()->second = 42; // OK, non-const value is modifiable // map.crbegin()->second = 42; // Error: cannot modify the const value }

Possible output:

Print out in reverse order using const reverse iterators: { "▓", 8 }; { "▓", 7 }; { "▒", 6 }; { "▒", 5 }; { "░", 4 }; { "░", 3 }; { "█", 2 }; { "█", 1 };

[edit] See also

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