Struct rustc::ty::sty::DebruijnIndex

pub struct DebruijnIndex(u32);

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

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Methods

impl DebruijnIndex

#[must_use] pub const fn shifted_in(self, amount: u32) -> DebruijnIndex

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

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Returns the resulting index when this value is moved into amount number of new binders. So e.g. if you had

for<'a> fn(&'a x)

and you wanted to change to

for<'a> fn(for<'b> fn(&'a x))

you would need to shift the index for 'a into 1 new binder.

pub fn shift_in(&mut self, amount: u32)

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

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Update this index in place by shifting it "in" through amount number of binders.

#[must_use] pub const fn shifted_out(self, amount: u32) -> DebruijnIndex

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

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Returns the resulting index when this value is moved out from amount number of new binders.

pub fn shift_out(&mut self, amount: u32)

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

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Update in place by shifting out from amount binders.

pub fn shifted_out_to_binder(self, to_binder: DebruijnIndex) -> Self

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

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Adjusts any Debruijn Indices so as to make to_binder the innermost binder. That is, if we have something bound at to_binder, it will now be bound at INNERMOST. This is an appropriate thing to do when moving a region out from inside binders:

            for<'a>   fn(for<'b>   for<'c>   fn(&'a u32), _)
// Binder:  D3           D2        D1            ^^

Here, the region 'a would have the debruijn index D3, because it is the bound 3 binders out. However, if we wanted to refer to that region 'a in the second argument (the _), those two binders would not be in scope. In that case, we might invoke shift_out_to_binder(D3). This would adjust the debruijn index of 'a to D1 (the innermost binder).

If we invoke shift_out_to_binder and the region is in fact bound by one of the binders we are shifting out of, that is an error (and should fail an assertion failure).

Trait Implementations

impl Copy for DebruijnIndex

impl Clone for DebruijnIndex

fn clone(&self) -> DebruijnIndex

Returns a copy of the value.

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

Performs copy-assignment from source.

impl PartialEq for DebruijnIndex

fn eq(&self, other: &DebruijnIndex) -> bool

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

fn ne(&self, other: &DebruijnIndex) -> bool

This method tests for !=.

impl Eq for DebruijnIndex

fn assert_receiver_is_total_eq(&self)

impl Hash for DebruijnIndex

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where     H: Hasher,

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

impl PartialOrd for DebruijnIndex

fn partial_cmp(&self, other: &DebruijnIndex) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &DebruijnIndex) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &DebruijnIndex) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &DebruijnIndex) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &DebruijnIndex) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Ord for DebruijnIndex

fn cmp(&self, other: &DebruijnIndex) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl Decodable for DebruijnIndex

fn decode<__D: Decoder>(d: &mut __D) -> Result<DebruijnIndex, __D::Error>

🔬 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 Encodable for DebruijnIndex

fn encode<__S: Encoder>(&self, s: &mut __S) -> Result<(), __S::Error>

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

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impl Idx for DebruijnIndex

fn new(value: usize) -> Self

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

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fn index(self) -> usize

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

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fn increment_by(&mut self, amount: usize)

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

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impl Step for DebruijnIndex

fn steps_between(start: &Self, end: &Self) -> Option<usize>

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

likely to be replaced by finer-grained traits

Returns the number of steps between two step objects. The count is inclusive of start and exclusive of end.

fn replace_one(&mut self) -> Self

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

likely to be replaced by finer-grained traits

Replaces this step with 1, returning itself

fn replace_zero(&mut self) -> Self

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

likely to be replaced by finer-grained traits

Replaces this step with 0, returning itself

fn add_one(&self) -> Self

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

likely to be replaced by finer-grained traits

Adds one to this step, returning the result

fn sub_one(&self) -> Self

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

likely to be replaced by finer-grained traits

Subtracts one to this step, returning the result

fn add_usize(&self, u: usize) -> Option<Self>

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

likely to be replaced by finer-grained traits

Add an usize, returning None on overflow

impl Debug for DebruijnIndex

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

Formats the value using the given formatter.

impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for DebruijnIndex

fn hash_stable<W: StableHasherResult>(     &self,     __ctx: &mut StableHashingContext<'a>,     __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?