pub(crate) struct MaybeItem<'a, 'b, K: Keyword>(Option<&'a Item<'b, K>>);
Expand description
Represents an Item that might not be present, whose arguments we want to inspect. If the Item is there, this acts like a proxy to the item; otherwise, it treats the item as having no arguments.
Tuple Fields§
§0: Option<&'a Item<'b, K>>
Implementations§
Source§impl<'a, 'b, K: Keyword> MaybeItem<'a, 'b, K>
impl<'a, 'b, K: Keyword> MaybeItem<'a, 'b, K>
Sourcepub(crate) fn from_option(opt: Option<&'a Item<'b, K>>) -> Self
pub(crate) fn from_option(opt: Option<&'a Item<'b, K>>) -> Self
Construct a MaybeItem from an Option reference to an item.
Sourcepub(crate) fn parse_arg<V: FromStr>(&self, idx: usize) -> Result<Option<V>>
Available on crate feature routerdesc
only.
pub(crate) fn parse_arg<V: FromStr>(&self, idx: usize) -> Result<Option<V>>
routerdesc
only.If this item is present, parse its argument at position idx
.
Treat the absence or malformedness of the argument as an error,
but treat the absence of this item as acceptable.
Sourcepub(crate) fn args_as_str(&self) -> Option<&str>
pub(crate) fn args_as_str(&self) -> Option<&str>
If this item is present, return its arguments as a single string.
Auto Trait Implementations§
impl<'a, 'b, K> Freeze for MaybeItem<'a, 'b, K>
impl<'a, 'b, K> !RefUnwindSafe for MaybeItem<'a, 'b, K>
impl<'a, 'b, K> !Send for MaybeItem<'a, 'b, K>
impl<'a, 'b, K> !Sync for MaybeItem<'a, 'b, K>
impl<'a, 'b, K> Unpin for MaybeItem<'a, 'b, K>
impl<'a, 'b, K> !UnwindSafe for MaybeItem<'a, 'b, K>
Blanket Implementations§
§impl<'a, T, E> AsTaggedExplicit<'a, E> for Twhere
T: 'a,
impl<'a, T, E> AsTaggedExplicit<'a, E> for Twhere
T: 'a,
§impl<'a, T, E> AsTaggedImplicit<'a, E> for Twhere
T: 'a,
impl<'a, T, E> AsTaggedImplicit<'a, E> for Twhere
T: 'a,
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Converts
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
, which can then be
downcast
into Box<dyn ConcreteType>
where ConcreteType
implements Trait
.§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Converts
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
, which can then be further
downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
.§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Converts
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s.§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Converts
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s.§impl<T> Instrument for T
impl<T> Instrument for T
§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
Converts
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
Converts
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more