Struct rustc_infer::traits::specialization_graph::Graph

pub struct Graph {
    pub parent: HashMap<DefId, DefId, BuildHasherDefault<FxHasher>>,
    pub children: HashMap<DefId, Children, BuildHasherDefault<FxHasher>>,
    pub has_errored: Option<ErrorGuaranteed>,
}

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: HashMap<DefId, DefId, BuildHasherDefault<FxHasher>>

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

children: HashMap<DefId, Children, BuildHasherDefault<FxHasher>>

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.

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