Enum rustc::ty::layout::FieldPlacement

pub enum FieldPlacement {
    Union(usize),
    Array {
        stride: Size,
        count: u64,
    },
    Arbitrary {
        offsets: Vec<Size>,
        memory_index: Vec<u32>,
    },
}

🔬 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?

Describes how the fields of a type are located in memory.

Variants

Union(usize)

🔬 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?

All fields start at no offset. The usize is the field count.

Array

🔬 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?

Array/vector-like placement, with all fields of identical types.

Fields of Array

stride: Size	🔬 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?
count: u64	🔬 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?

Arbitrary

🔬 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?

Struct-like placement, with precomputed offsets.

Fields are guaranteed to not overlap, but note that gaps before, between and after all the fields are NOT always padding, and as such their contents may not be discarded. For example, enum variants leave a gap at the start, where the discriminant field in the enum layout goes.

Fields of Arbitrary

offsets: Vec<Size>	🔬 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? Offsets for the first byte of each field, ordered to match the source definition order. This vector does not go in increasing order.
memory_index: Vec<u32>	🔬 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? Maps source order field indices to memory order indices, depending how fields were permuted.

Methods

impl FieldPlacement

pub fn count(&self) -> usize

🔬 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?

pub fn offset(&self, i: usize) -> Size

🔬 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?

pub fn memory_index(&self, i: usize) -> usize

🔬 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?

pub fn index_by_increasing_offset<'a>(
    &'a self
) -> impl Iterator<Item = usize> + 'a

🔬 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?

Get source indices of the fields by increasing offsets.

Trait Implementations

impl PartialEq for FieldPlacement

fn eq(&self, __arg_0: &FieldPlacement) -> bool

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

fn ne(&self, __arg_0: &FieldPlacement) -> bool

This method tests for !=.

impl Eq for FieldPlacement

impl Hash for FieldPlacement

fn hash<__H: Hasher>(&self, __arg_0: &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 Debug for FieldPlacement

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'gcx> HashStable<StableHashingContext<'gcx>> for FieldPlacement

fn hash_stable<W: StableHasherResult>(
    &self,
    hcx: &mut StableHashingContext<'gcx>,
    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?