Struct rustc_abi::VariantIdx

pub struct VariantIdx {
    pub(crate) private: u32,
}

The source-order index of a variant in a type.

For enums, these are always 0..variant_count, regardless of any custom discriminants that may have been defined, and including any variants that may end up uninhabited due to field types. (Some of the variants may not be present in a monomorphized ABI Variants, but those skipped variants are always counted when determining the index.)

structs, tuples, and unionss are considered to have a single variant with variant index zero, aka FIRST_VARIANT.

Fields

private: u32

Implementations

impl VariantIdx

pub const MAX_AS_U32: u32 = 4_294_967_040u32

Maximum value the index can take, as a u32.

pub const MAX: Self = _

Maximum value the index can take.

pub const fn from_usize(value: usize) -> Self

Creates a new index from a given usize.

Panics

Will panic if value exceeds MAX.

pub const fn from_u32(value: u32) -> Self

Creates a new index from a given u32.

Panics

Will panic if value exceeds MAX.

pub const unsafe fn from_u32_unchecked(value: u32) -> Self

Creates a new index from a given u32.

Safety

The provided value must be less than or equal to the maximum value for the newtype. Providing a value outside this range is undefined due to layout restrictions.

Prefer using from_u32.

pub const fn index(self) -> usize

Extracts the value of this index as a usize.

pub const fn as_u32(self) -> u32

Extracts the value of this index as a u32.

pub const fn as_usize(self) -> usize

Extracts the value of this index as a usize.

Trait Implementations

impl Add<usize> for VariantIdx

type Output = VariantIdx

The resulting type after applying the + operator.

fn add(self, other: usize) -> Self

Performs the + operation.

impl Clone for VariantIdx

fn clone(&self) -> VariantIdx

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for VariantIdx

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

Formats the value using the given formatter.

impl<D: Decoder> Decodable<D> for VariantIdx

fn decode(d: &mut D) -> Self

impl<E: Encoder> Encodable<E> for VariantIdx

fn encode(&self, e: &mut E)

impl From<VariantIdx> for u32

fn from(v: VariantIdx) -> u32

Converts to this type from the input type.

impl From<VariantIdx> for usize

fn from(v: VariantIdx) -> usize

Converts to this type from the input type.

impl From<u32> for VariantIdx

fn from(value: u32) -> Self

Converts to this type from the input type.

impl From<usize> for VariantIdx

fn from(value: usize) -> Self

Converts to this type from the input type.

impl Hash for VariantIdx

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<__CTX> HashStable<__CTX> for VariantIdxwhere __CTX: HashStableContext,

fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

impl Idx for VariantIdx

fn new(value: usize) -> Self

fn index(self) -> usize

fn increment_by(&mut self, amount: usize)

fn plus(self, amount: usize) -> Self

impl Ord for VariantIdx

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<VariantIdx> for VariantIdx

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

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

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<VariantIdx> for VariantIdx

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

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

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

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

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

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

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

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

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

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

impl Step for VariantIdx

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

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

Returns the number of successor steps required to get from start to end.

fn forward_checked(start: Self, u: usize) -> Option<Self>

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

Returns the value that would be obtained by taking the successor of self count times.

fn backward_checked(start: Self, u: usize) -> Option<Self>

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

Returns the value that would be obtained by taking the predecessor of self count times.

fn forward(start: Self, count: usize) -> Self

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

Returns the value that would be obtained by taking the successor of self count times.

unsafe fn forward_unchecked(start: Self, count: usize) -> Self

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

Returns the value that would be obtained by taking the successor of self count times.

fn backward(start: Self, count: usize) -> Self

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

Returns the value that would be obtained by taking the predecessor of self count times.

unsafe fn backward_unchecked(start: Self, count: usize) -> Self

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

Returns the value that would be obtained by taking the predecessor of self count times.

impl Copy for VariantIdx

impl Eq for VariantIdx

impl StructuralEq for VariantIdx

impl StructuralPartialEq for VariantIdx

impl TrustedStep for VariantIdx

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 4 bytes