Struct rustc::ty::ParamEnv[][src]

pub struct ParamEnv<'tcx> {
    pub caller_bounds: &'tcx Slice<Predicate<'tcx>>,
    pub reveal: Reveal,
}
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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

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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.

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

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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().

Methods

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

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

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

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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.

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

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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.

NB. If you want to have predicates in scope, use ParamEnv::new, or invoke param_env.with_reveal_all().

🔬 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?

Construct a trait environment with the given set of predicates.

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

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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.

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

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Returns this same environment but with no caller bounds.

🔬 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?

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.

NB: 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<'a, 'tcx> HashStable<StableHashingContext<'a>> for ParamEnv<'tcx>
[src]

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

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Given an instance of this key, what crate is it referring to? This is used to find the provider. Read more

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In the event that a cycle occurs, if no explicit span has been given for a query with key self, what span should we use? Read more

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

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

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

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

🔬 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?

🔬 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?

🔬 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?

🔬 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?

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

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True if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free. Read more

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

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True if this self has any regions that escape binder (and hence are not bound by it). Read more

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

🔬 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?

"Free" regions in this context means that it has any region that is not (a) erased or (b) late-bound. Read more

🔬 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?

True if there any any un-erased free regions.

🔬 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?

Indicates whether this value references only 'global' types/lifetimes that are the same regardless of what fn we are in. This is used for caching. Read more

🔬 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?

True if there are any late-bound regions

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

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

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

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

Formats the value using the given formatter. Read more

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

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

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

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

Feeds this value into the given [Hasher]. Read more

Feeds a slice of this type into the given [Hasher]. Read more

Auto Trait Implementations

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

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