std::optional<T>::end
From cppreference.com
constexpr iterator end() noexcept; |
(since C++26) | |
constexpr const_iterator end() const noexcept; |
(since C++26) | |
Returns a past-the-end iterator. Equivalent to return begin() + has_value();.
Contents |
[edit] Parameters
(none)
[edit] Return value
Past-the-end iterator
[edit] Complexity
Constant.
[edit] Notes
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_optional_range_support |
202406L |
(C++26) | Range support for std::optional
|
[edit] Example
Run this code
#include <optional> #include <print> int main() { constexpr std::optional<int> none = std::nullopt; // optional @1 constexpr std::optional<int> some = 42; // optional @2 static_assert(none.begin() == none.end()); static_assert(some.begin() != some.end()); // ranged-for loop support for (int i : none) std::println("Optional @1 has a value of {}", i); for (int i : some) std::println("Optional @2 has a value of {}", i); }
Output:
Optional @2 has a value of 42
[edit] See also
(C++26) |
returns an iterator to the beginning (public member function) |