Struct rustc_trait_selection::traits::specialization_graph::Graph

pub struct Graph {
    pub parent: UnordMap<DefId, DefId>,
    pub children: UnordMap<DefId, Children>,
}

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.

Fields

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.

Implementations

impl Graph

pub fn new() -> Graph

pub fn parent(&self, child: DefId) -> DefId

The parent of a given impl, which is the DefId of the trait when the impl is a “specialization root”.

Trait Implementations

impl<'tcx> ArenaAllocatable<'tcx> for Graph

fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut Graph

fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = Graph>, ) -> &'a mut [Graph]

impl Debug for Graph

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

Formats the value using the given formatter.

impl<'a, 'tcx> Decodable<CacheDecoder<'a, 'tcx>> for &'tcx Graph

fn decode(d: &mut CacheDecoder<'a, 'tcx>) -> &'tcx Graph

impl<__D> Decodable<__D> for Graph

where __D: TyDecoder,

fn decode(__decoder: &mut __D) -> Graph

impl<__E> Encodable<__E> for Graph

where __E: TyEncoder,

fn encode(&self, __encoder: &mut __E)

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

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.

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.

impl<'__ctx> HashStable<StableHashingContext<'__ctx>> for Graph

fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher<SipHasher128>, )

impl<'tcx, D> RefDecodable<'tcx, D> for Graph

where D: TyDecoder<I = TyCtxt<'tcx>>,

fn decode(decoder: &mut D) -> &'tcx Graph

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: 64 bytes