Struct gc_sequence::map_result::MapError

#[must_use = "sequences do nothing unless stepped"]
pub struct MapError<S, F>(_, _);

Methods

impl<S, F> MapError<S, F>

pub fn new(s: S, f: F) -> MapError<S, F>

Trait Implementations

impl<'gc, S, F, I, E, R> Sequence<'gc> for MapError<S, F> where
    S: Sequence<'gc, Output = Result<I, E>>,
    F: 'static + FnOnce(E) -> R, 

type Output = Result<I, R>

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

impl<S, F> Drop for MapError<S, F>

fn drop(&mut self)

Executes the destructor for this type.

impl<S: Debug, F: Debug> Debug for MapError<S, F>

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

Formats the value using the given formatter.

impl<S, F> Collect for MapError<S, F> where
    S: Collect,
    Option<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.