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();.
Return value
Past-the-end iterator
Complexity
Constant.
Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_optional_range_support |
202406L |
(C++26) | Range support for std::optional |
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
See also
(C++26) |
returns an iterator to the beginning (public member function) |