Struct Present 

pub struct Present;

Marker indicating a field is present with a concrete value.

Trait Implementations

impl Presence for Present

type OptionOrSelf = Present

Presence when combined with Option.

type Or<Other: Presence> = Present

Result of merging this presence with another.

type RemainderFrom<Source: Presence> = Absent

Remainder when extracting Self: Present/Optional → Absent, Absent → Source.

type Output<T> = T

Container type (T, Option<T>, or PhantomData<T>).

fn or<T, Other: Presence>( self_: <Self as Presence>::Output<T>, _other: Other::Output<T>, ) -> <<Self as Presence>::Or<Other> as Presence>::Output<T>

Merge two values, preferring the first if present.

fn option_or_self<T>( option: Option<T>, self_: <Self as Presence>::Output<T>, ) -> <<Self as Presence>::OptionOrSelf as Presence>::Output<T>

Convert an Option into the appropriate presence state.

impl Split<Absent> for Present

fn split<T>(value: T) -> (PhantomData<T>, T)

Split a value into selected and remainder parts.

impl Split<Optional> for Present

fn split<T>(value: T) -> (Option<T>, PhantomData<T>)

Split a value into selected and remainder parts.

impl Split<Present> for Present

fn split<T>(value: T) -> (T, PhantomData<T>)

Split a value into selected and remainder parts.

impl TrySplit<Present> for Optional

fn try_split<T>(value: Option<T>) -> Result<(T, PhantomData<T>), Option<T>>

Try to split a value into selected and remainder parts.