Struct rustc_target::abi::FieldIdx

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pub struct FieldIdx {
    private: u32,
}
Expand description

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

This is how most code after type checking refers to fields, rather than using names (as names have hygiene complications and more complex lookup).

Particularly for repr(Rust) types, this may not be the same as layout order. (It is for repr(C) structs, however.)

For example, in the following types,

enum Demo1 {
   Variant0 { a: Never, b: i32 } = 100,
   Variant1 { c: u8, d: u64 } = 10,
}
struct Demo2 { e: u8, f: u16, g: u8 }

b is FieldIdx(1) in VariantIdx(0), d is FieldIdx(1) in VariantIdx(1), and f is FieldIdx(1) in VariantIdx(0).

Fields§

§private: u32

Implementations§

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impl FieldIdx

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pub const MAX_AS_U32: u32 = 4_294_967_040u32

Maximum value the index can take, as a u32.

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pub const MAX: Self = _

Maximum value the index can take.

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

Creates a new index from a given usize.

Panics

Will panic if value exceeds MAX.

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

Creates a new index from a given u32.

Panics

Will panic if value exceeds MAX.

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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.

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pub const fn index(self) -> usize

Extracts the value of this index as a usize.

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pub const fn as_u32(self) -> u32

Extracts the value of this index as a u32.

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pub const fn as_usize(self) -> usize

Extracts the value of this index as a usize.

Trait Implementations§

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impl Add<usize> for FieldIdx

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type Output = FieldIdx

The resulting type after applying the + operator.
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fn add(self, other: usize) -> Self

Performs the + operation. Read more
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impl Clone for FieldIdx

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fn clone(&self) -> FieldIdx

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for FieldIdx

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

Formats the value using the given formatter. Read more
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impl<D: Decoder> Decodable<D> for FieldIdx

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

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

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

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impl From<FieldIdx> for u32

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fn from(v: FieldIdx) -> u32

Converts to this type from the input type.
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impl From<FieldIdx> for usize

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fn from(v: FieldIdx) -> usize

Converts to this type from the input type.
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impl From<u32> for FieldIdx

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fn from(value: u32) -> Self

Converts to this type from the input type.
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impl From<usize> for FieldIdx

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fn from(value: usize) -> Self

Converts to this type from the input type.
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impl Hash for FieldIdx

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

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl<__CTX> HashStable<__CTX> for FieldIdxwhere __CTX: HashStableContext,

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

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impl Idx for FieldIdx

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fn new(value: usize) -> Self

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fn index(self) -> usize

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fn increment_by(&mut self, amount: usize)

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

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impl Ord for FieldIdx

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

This method returns an Ordering between self and other. Read more
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fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values. Read more
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fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values. Read more
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fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval. Read more
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impl PartialEq<FieldIdx> for FieldIdx

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

This method tests for self and other values to be equal, and is used by ==.
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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.
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impl PartialOrd<FieldIdx> for FieldIdx

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

This method returns an ordering between self and other values if one exists. Read more
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fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

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

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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. Read more
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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. Read more
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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. Read more
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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. Read more
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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. Read more
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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. Read more
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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. Read more
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impl Copy for FieldIdx

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impl Eq for FieldIdx

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impl StructuralEq for FieldIdx

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impl StructuralPartialEq for FieldIdx

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impl TrustedStep for FieldIdx

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for Twhere T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

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