Enum gc_sequence::then::Then

#[must_use = "sequences do nothing unless stepped"]
pub enum Then<'gc, S, F> where
    S: Sequence<'gc>,  {
    First(S, Option<StaticCollect<F>>),
    Second(Option<(S::Output, StaticCollect<F>)>),
}

Variants

First(S, Option<StaticCollect<F>>)

Second(Option<(S::Output, StaticCollect<F>)>)

Implementations

impl<'gc, S, F> Then<'gc, S, F> where
    S: Sequence<'gc>, 

pub fn new(s: S, f: F) -> Then<'gc, S, F>

Trait Implementations

impl<'gc, S, F> Collect for Then<'gc, S, F> where
    S: Sequence<'gc>,
    S: Collect,
    Option<StaticCollect<F>>: Collect,
    Option<(S::Output, StaticCollect<F>)>: Collect, 

fn needs_trace() -> bool

As an optimization, if this type can never hold a Gc pointer and trace is unnecessary to call, you may implement this method and return false. The default implementation returns true, signaling that Collect::trace must be called.

fn trace(&self, cc: CollectionContext<'_>)

Must call Collect::trace on all held Gc pointers. If this type holds inner types that implement Collect, a valid implementation would simply call Collect::trace on all the held values to ensure this.

impl<'gc, S: Debug, F: Debug> Debug for Then<'gc, S, F> where
    S: Sequence<'gc>,
    S::Output: Debug, 

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

Formats the value using the given formatter.

impl<'gc, S, F> MustNotImplDrop for Then<'gc, S, F> where
    S: Sequence<'gc>, 

impl<'gc, S, F, R> Sequence<'gc> for Then<'gc, S, F> where
    S: Sequence<'gc>,
    S::Output: Collect,
    F: 'static + FnOnce(MutationContext<'gc, '_>, S::Output) -> R, 

type Output = R

fn step(&mut self, mc: MutationContext<'gc, '_>) -> Option<R>