None<T> class final

Variant representing a missing value.

Inheritance

Constructors

None()
Creates a constant None variant representing the absence of a value.
const

Properties

hashCode → int
The hash code for this object.
no setteroverride
isEmpty → bool
Returns true if this is a None instance.
no setterinherited
isPresent → bool
Returns true if this is a Some instance.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

flatMap<R>(Optional<R> mapper(T value)) → Optional<R>
Transforms the value using a function that returns an Optional. Prevents nested structures like Optional<Optional<T>>.
inherited
map<R>(R mapper(T value)) → Optional<R>
Transforms the value if present using mapper.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
override
valueOr(T fallback) → T
Returns the value if present, otherwise returns fallback.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
override