Struct rustc_metadata::schema::Lazy

#[must_use]
pub struct Lazy<T> {
    pub position: usize,
    _marker: PhantomData<T>,
}

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A value of type T referred to by its absolute position in the metadata, and which can be decoded lazily.

Metadata is effective a tree, encoded in post-order, and with the root's position written next to the header. That means every single Lazy points to some previous location in the metadata and is part of a larger node.

The first Lazy in a node is encoded as the backwards distance from the position where the containing node starts and where the Lazy points to, while the rest use the forward distance from the previous Lazy. Distances start at 1, as 0-byte nodes are invalid. Also invalid are nodes being referred in a different order than they were encoded in.

Fields

position: usize

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_marker: PhantomData<T>

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

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Methods

impl<'a, 'tcx: 'a, T: Decodable> Lazy<T>

pub fn decode<M: Metadata<'a, 'tcx>>(self, meta: M) -> T

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

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impl<T> Lazy<T>

pub fn with_position(position: usize) -> Lazy<T>

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pub fn min_size() -> usize

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Returns the minimum encoded size of a value of type T.

Trait Implementations

impl<'a, 'tcx, T> SpecializedEncoder<Lazy<T>> for EncodeContext<'a, 'tcx>

fn specialized_encode(&mut self, lazy: &Lazy<T>) -> Result<(), Self::Error>

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Encode the value in a manner specific to this encoder state.

impl<'a, 'tcx, T> SpecializedDecoder<Lazy<T>> for DecodeContext<'a, 'tcx>

fn specialized_decode(&mut self) -> Result<Lazy<T>, Self::Error>

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

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Decode a value in a manner specific to this decoder state.

impl<T> Copy for Lazy<T>

impl<T> Clone for Lazy<T>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> UseSpecializedEncodable for Lazy<T>

fn default_encode<E>(&self, &mut E) -> Result<(), <E as Encoder>::Error> where     E: Encoder,

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Defaults to returning an error (see SpecializationError).

impl<T> UseSpecializedDecodable for Lazy<T>

fn default_decode<D>(&mut D) -> Result<Self, <D as Decoder>::Error> where     D: Decoder,

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Defaults to returning an error (see SpecializationError).

impl<CTX, T> HashStable<CTX> for Lazy<T>

fn hash_stable<W: StableHasherResult>(     &self,     _: &mut CTX,     _: &mut StableHasher<W> )

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

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