std::nullopt
From cppreference.com
C++
Utilities library
|
|
std::optional
Member functions | ||||
(C++17) | ||||
(C++17) | ||||
(C++17) | ||||
Observers | ||||
(C++17)(C++17) | ||||
(C++17)(C++17) | ||||
(C++17) | ||||
(C++17) | ||||
Monadic operations | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
Modifiers | ||||
(C++17) | ||||
(C++17) | ||||
(C++17) | ||||
Non-member functions | ||||
(C++17)(C++17)(C++17)(C++17)(C++17)(C++17)(C++20) | ||||
(C++17) | ||||
(C++17) | ||||
Deduction guides | ||||
Helper classes | ||||
(C++17) | ||||
(C++17) | ||||
(C++17) | ||||
(C++17) | ||||
Helper objects | ||||
nullopt (C++17) | ||||
(C++17) |
Defined in header <optional>
|
||
inline constexpr nullopt_t nullopt{/*unspecified*/}; |
(since C++17) | |
std::nullopt
is a constant of type std::nullopt_t that is used to indicate optional
type with uninitialized state.
See also
(C++17) |
indicator of optional type with uninitialized state (class) |