Struct NotPresent 

pub struct NotPresent;

Part of a network document, that isn’t actually there.

Used as a standin in ns_type! calls in various netstatus each_variety.rs. The effect is as if the field were omitted from the containing type.

• When used as item(s) (ie, a field type when deriving NetdocParseable\[Fields\]): ignores any number of items with that field’s keyword during parsing, and emits none during encoding.

  (To reject documents containing this item, use Option<Void>, but note that the spec says unknown items should be ignored, which would normally include items which are merely missing from one variety.)

• When used as an argument (ie, a field type when deriving ItemValueParseable, or with netdoc(single_arg) when deriving NetdocParseable\[Fields\]): consumes no arguments during parsing, and emits none during encoding.

• When used as an object field (ie, netdoc(object) when deriving ItemValueParseable): rejects an object - failing the parse if one is present. (Functions similarly to Option<Void>, but prefer NotPresent as it’s clearer.)

There are bespoke impls of the multiplicity traits ItemSetMethods and ObjectSetMethods: don’t wrap this type in Option or Vec.

Trait Implementations

impl Clone for NotPresent

fn clone(&self) -> NotPresent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NotPresent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for NotPresent

fn default() -> NotPresent

Returns the “default value” for a type.

impl Hash for NotPresent

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl ItemArgumentParseable for NotPresent

Available on crate feature parse2 only.

fn from_args(_: &mut ArgumentStream<'_>) -> Result<NotPresent, ArgumentError>

Parse the argument

impl NetdocParseableFields for NotPresent

type Accumulator = NotPresentNetdocParseAccumulator

Available on crate feature parse2 only.

The partially-parsed set of items.

fn is_item_keyword(kw: KeywordRef<'_>) -> bool

Available on crate feature parse2 only.

Is this one of the keywords in this struct

fn accumulate_item( acc: &mut Self::Accumulator, item: UnparsedItem<'_>, ) -> Result<(), ErrorProblem>

Available on crate feature parse2 only.

Accumulate an item in this struct

fn finish(acc: Self::Accumulator) -> Result<Self, ErrorProblem>

Available on crate feature parse2 only.

Finish

impl Ord for NotPresent

fn cmp(&self, other: &NotPresent) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for NotPresent

fn eq(&self, other: &NotPresent) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for NotPresent

fn partial_cmp(&self, other: &NotPresent) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for NotPresent

impl Eq for NotPresent

impl StructuralPartialEq for NotPresent