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std::optional<T>::end

From cppreference.com
< cpp‎ | utility‎ | optional
 
 
Utilities library
General utilities
Relational operators (deprecated in C++20)
 
 
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();.

range-begin-end.svg

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

#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) [edit]