Enum rustc::hir::lowering::ImplTraitContext

enum ImplTraitContext {
    Universal(DefId),
    Existential(DefId),
    Disallowed,
}

🔬 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?

Variants

Universal(DefId)

🔬 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?

Treat impl Trait as shorthand for a new universal generic parameter. Example: fn foo(x: impl Debug), where impl Debug is conceptually equivalent to a fresh universal parameter like fn foo<T: Debug>(x: T).

We store a DefId here so we can look up necessary information later

Existential(DefId)

🔬 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?

Treat impl Trait as shorthand for a new universal existential parameter. Example: fn foo() -> impl Debug, where impl Debug is conceptually equivalent to a fresh existential parameter like abstract type T; fn foo() -> T.

We store a DefId here so we can look up necessary information later

Disallowed

🔬 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?

impl Trait is not accepted in this position.

Trait Implementations

impl Clone for ImplTraitContext

fn clone(&self) -> ImplTraitContext

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ImplTraitContext

impl Debug for ImplTraitContext

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

Formats the value using the given formatter.