folly::Optional

Synopsis

Declared in <folly/Optional.h>

template<class Value>
class Optional;

Type Aliases

Name	Description
`promise_type`	The coroutine promise type that enables using Optional with co_await.
`value_type`	The type of the value stored in the Optional.

Member Functions

Name	Description
`Optional` [constructor]	Constructors
`operator=`	Assignment operators
`assign`	`assign` overloads
`clear`	Set the Optional to None methodset Modifiers
`emplace`	`emplace` overloads
`get_pointer`	`get_pointer` overloads
`hasValue`	Does this Optional have a value. methodset Observers
`has_value`	Does this Optional have a value. methodset Observers
`operator*`	Get the value. Must have value. methodset Getters
`operator->`	Get the value. Must have value. methodset Getters
`reset`	Set the Optional to None methodset Modifiers
`swap`	Swaps the contents of this Optional with another. methodset Modifiers
`toStdOptional`	`toStdOptional` overloads
`value`	Get the value. Must have value. methodset Getters
`value_or`	`value_or` overloads
`operator bool`	Does this Optional have a value. methodset Observers
`operator std::optional<Value>`	Conversion operators

Friends

Name	Description
`folly::make_optional`	Creates an Optional whose value is constructed in-place from a list.
`folly::make_optional`	Creates an Optional whose value is constructed in-place.
`folly::make_optional`	Creates an Optional deducing the value type from the argument.

Non-Member Functions

Name	Description
`getCurrentThreadName`	Equivalent to getThreadName(std::this_thread::get_id());
`getExecutorBlockingContext`	Returns the current thread's executor blocking context, if any is active.
`getThreadName`	Get the name of the given thread, or nothing if an error occurs or the functionality is not available.
`get_pointer`	Returns a pointer to the value of an Optional, or nullptr if empty.
`get_pointer`	Returns a pointer to the value of an Optional, or nullptr if empty.
`make_optional`	Creates an Optional whose value is constructed in-place from a list.
`make_optional`	Creates an Optional whose value is constructed in-place.
`make_optional`	Creates an Optional deducing the value type from the argument.
`operator co_await`	Enables using folly::Optional with the co_await operator.
`operator!=`	Compares two Optionals for inequality.
`operator!=`	Compares an Optional with a value for inequality.
`operator<`	Deleted to forbid ordering an Optional against a bare value.
`operator<`	Orders two Optionals; an empty Optional sorts before any value.
`operator<`	Orders an Optional against None; nothing sorts before None.
`operator<=`	Orders an Optional against None.
`operator<=`	Orders two Optionals; an empty Optional sorts before any value.
`operator<=`	Deleted to forbid ordering an Optional against a bare value.
`operator==`	Tests whether an Optional is empty.
`operator==`	Compares two Optionals for equality.
`operator==`	Compares an Optional with a value for equality.
`operator>`	Orders two Optionals; an empty Optional sorts before any value.
`operator>`	Orders an Optional against None; a value sorts after None.
`operator>`	Deleted to forbid ordering an Optional against a bare value.
`operator>=`	Deleted to forbid ordering an Optional against a bare value.
`operator>=`	Orders an Optional against None; any value sorts at or after None.
`operator>=`	Orders two Optionals; an empty Optional sorts before any value.
`swap`	Swaps the contents of two Optionals.
`tryUriUnescape`	Similar to tryUriUnescape above, but returning the unescaped string as a folly::Expected.
`coro::timed_wait`	Awaits `awaitable`, giving up after `duration` elapses.
`settings::getSettingsMeta`	Returns the metadata for a setting by name, if it exists.