pub struct Graph {
    pub parent: UnordMap<DefId, DefId>,
    pub children: UnordMap<DefId, Children>,
    pub has_errored: Option<ErrorGuaranteed>,
}
Expand description

A per-trait graph of impls in specialization order. At the moment, this graph forms a tree rooted with the trait itself, with all other nodes representing impls, and parent-child relationships representing specializations.

The graph provides two key services:

  • Construction. This implicitly checks for overlapping impls (i.e., impls that overlap but where neither specializes the other – an artifact of the simple “chain” rule.

  • Parent extraction. In particular, the graph can give you the immediate parents of a given specializing impl, which is needed for extracting default items amongst other things. In the simple “chain” rule, every impl has at most one parent.

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§parent: UnordMap<DefId, DefId>

All impls have a parent; the “root” impls have as their parent the def_id of the trait.

§children: UnordMap<DefId, Children>

The “root” impls are found by looking up the trait’s def_id.

§has_errored: Option<ErrorGuaranteed>

Whether an error was emitted while constructing the graph.

Trait Implementations§

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impl<'tcx> GraphExt<'tcx> for Graph

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fn insert( &mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId, overlap_mode: OverlapMode ) -> Result<Option<FutureCompatOverlapError<'tcx>>, OverlapError<'tcx>>

Insert a local impl into the specialization graph. If an existing impl conflicts with it (has overlap, but neither specializes the other), information about the area of overlap is returned in the Err.

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fn record_impl_from_cstore( &mut self, tcx: TyCtxt<'tcx>, parent: DefId, child: DefId )

Insert cached metadata mapping from a child impl back to its parent.

Auto Trait Implementations§

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impl RefUnwindSafe for Graph

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impl Send for Graph

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impl Sync for Graph

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impl Unpin for Graph

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impl UnwindSafe for Graph

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 72 bytes