std::optional<T>::end
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std::optional
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optional::end
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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] 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