Struct rustc::ty::CrateVariancesMap

pub struct CrateVariancesMap {
    pub variances: FxHashMap<DefId, Rc<Vec<Variance>>>,
    pub empty_variance: Rc<Vec<Variance>>,
}

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

The crate variances map is computed during typeck and contains the variance of every item in the local crate. You should not use it directly, because to do so will make your pass dependent on the HIR of every item in the local crate. Instead, use tcx.variances_of() to get the variance for a particular item.

Fields

variances: FxHashMap<DefId, Rc<Vec<Variance>>>

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

For each item with generics, maps to a vector of the variance of its generics. If an item has no generics, it will have no entry.

empty_variance: Rc<Vec<Variance>>

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

An empty vector, useful for cloning.

Trait Implementations

impl<'gcx> HashStable<StableHashingContext<'gcx>> for CrateVariancesMap

fn hash_stable<W: StableHasherResult>(
    &self,
    hcx: &mut StableHashingContext<'gcx>,
    hasher: &mut StableHasher<W>
)

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?