std::optional<T>:: end

Returns a past-the-end iterator. Equivalent to return begin ( ) + has_value ( ) ; .

Parameters

(none)

Return value

Past-the-end iterator

Complexity

Constant.

Notes

Example

#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);
}

Optional @2 has a value of 42

See also