[][src]Struct rustc_middle::ty::ParamEnv

pub struct ParamEnv<'tcx> {
    pub caller_bounds: &'tcx List<Predicate<'tcx>>,
    pub reveal: Reveal,
    pub def_id: Option<DefId>,
}
⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

When type checking, we use the ParamEnv to track details about the set of where-clauses that are in scope at this particular point.

Fields

caller_bounds: &'tcx List<Predicate<'tcx>>
⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Obligations that the caller must satisfy. This is basically the set of bounds on the in-scope type parameters, translated into Obligations, and elaborated and normalized.

reveal: Reveal
⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Typically, this is Reveal::UserFacing, but during codegen we want Reveal::All -- note that this is always paired with an empty environment. To get that, use ParamEnv::reveal().

def_id: Option<DefId>
⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

If this ParamEnv comes from a call to tcx.param_env(def_id), register that def_id (useful for transitioning to the chalk trait solver).

Implementations

impl<'tcx> ParamEnv<'tcx>[src]

pub fn empty() -> Self[src]

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Construct a trait environment suitable for contexts where there are no where-clauses in scope. Hidden types (like impl Trait) are left hidden, so this is suitable for ordinary type-checking.

pub fn reveal_all() -> Self[src]

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Construct a trait environment with no where-clauses in scope where the values of all impl Trait and other hidden types are revealed. This is suitable for monomorphized, post-typeck environments like codegen or doing optimizations.

N.B., if you want to have predicates in scope, use ParamEnv::new, or invoke param_env.with_reveal_all().

pub fn new(
    caller_bounds: &'tcx List<Predicate<'tcx>>,
    reveal: Reveal,
    def_id: Option<DefId>
) -> Self
[src]

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Construct a trait environment with the given set of predicates.

pub fn with_reveal_all(self) -> Self[src]

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Returns a new parameter environment with the same clauses, but which "reveals" the true results of projections in all cases (even for associated types that are specializable). This is the desired behavior during codegen and certain other special contexts; normally though we want to use Reveal::UserFacing, which is the default.

pub fn without_caller_bounds(self) -> Self[src]

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Returns this same environment but with no caller bounds.

pub fn and<T: TypeFoldable<'tcx>>(self, value: T) -> ParamEnvAnd<'tcx, T>[src]

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Creates a suitable environment in which to perform trait queries on the given value. When type-checking, this is simply the pair of the environment plus value. But when reveal is set to All, then if value does not reference any type parameters, we will pair it with the empty environment. This improves caching and is generally invisible.

N.B., we preserve the environment when type-checking because it is possible for the user to have wacky where-clauses like where Box<u32>: Copy, which are clearly never satisfiable. We generally want to behave as if they were true, although the surrounding function is never reachable.

Trait Implementations

impl<'tcx> Clone for ParamEnv<'tcx>[src]

impl<'tcx> Copy for ParamEnv<'tcx>[src]

impl<'tcx> Debug for ParamEnv<'tcx>[src]

impl<'tcx> Eq for ParamEnv<'tcx>[src]

impl<'tcx> Hash for ParamEnv<'tcx>[src]

impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for ParamEnv<'tcx>[src]

impl<'tcx> Key for ParamEnv<'tcx>[src]

type CacheSelector = DefaultCacheSelector

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

impl<'a, 'tcx> Lift<'tcx> for ParamEnv<'a>[src]

type Lifted = ParamEnv<'tcx>

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

impl<'tcx> PartialEq<ParamEnv<'tcx>> for ParamEnv<'tcx>[src]

impl<'tcx> StructuralEq for ParamEnv<'tcx>[src]

impl<'tcx> StructuralPartialEq for ParamEnv<'tcx>[src]

impl<'tcx> TypeFoldable<'tcx> for ParamEnv<'tcx>[src]

Auto Trait Implementations

impl<'tcx> !RefUnwindSafe for ParamEnv<'tcx>

impl<'tcx> !Send for ParamEnv<'tcx>

impl<'tcx> !Sync for ParamEnv<'tcx>

impl<'tcx> Unpin for ParamEnv<'tcx>

impl<'tcx> !UnwindSafe for ParamEnv<'tcx>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<'tcx, T> ArenaAllocatable<'tcx, ()> for T where
    T: Copy
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<'a, T> Captures<'a> for T where
    T: ?Sized
[src]

impl<T> Cast for T

impl<Ctxt, T> DepNodeParams<Ctxt> for T where
    Ctxt: DepContext,
    T: HashStable<<Ctxt as DepContext>::StableHashingContext> + Debug
[src]

impl<Q, K> Equivalent<K> for Q where
    K: Borrow<Q> + ?Sized,
    Q: Eq + ?Sized
[src]

impl<T> Erased for T[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> MaybeResult<T> for T[src]

type Error = !

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

impl<T> Same<T> for T

type Output = T

⚙️ This is an internal compiler API. (rustc_private)

This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml.

Should always be Self

impl<E> SpecializationError for E[src]

impl<'tcx, T> Subst<'tcx> for T where
    T: TypeFoldable<'tcx>, 
[src]

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

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

The type returned in the event of a conversion error.

impl<T> WithConstness for T[src]