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GenericParamVariance

dotscope::metadata::tables

Enum GenericParamVariance

pub enum GenericParamVariance {
    Invariant,
    Covariant,
    Contravariant,
}

Expand description

Variance classification of a generic parameter (ECMA-335 §II.22.20).

Returned by GenericParamAttributes::variance. The three variants are fixed by the standard and mutually exclusive — exactly one applies to any given generic parameter.

§Stability

The string returned by GenericParamVariance::as_str and by the Display impl is part of the stable public API. It is safe to persist (file, database, log line) and to parse.

Variants§

Invariant

No variance — exact type match required.

Corresponds to ECMA-335 variance bits 0x00 (and the reserved/undefined pattern 0x03).

Covariant

Covariant — type argument may be a more derived type.

Corresponds to ECMA-335 variance bit 0x01 and the C# out keyword (e.g. IEnumerable<out T>).

Contravariant

Contravariant — type argument may be a less derived type.

Corresponds to ECMA-335 variance bit 0x02 and the C# in keyword (e.g. Action<in T>).

Implementations§

impl GenericParamVariance

pub const fn as_str(&self) -> &'static str

Returns a stable &'static str identifier for this variance.

Identifiers are lowercase ("invariant", "covariant", "contravariant"). They are part of the stable public API and safe to persist.

Trait Implementations§

impl Clone for GenericParamVariance

fn clone(&self) -> GenericParamVariance

Returns a duplicate of the value. Read more

1.0.0 (const: unstable) · Source§

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

Performs copy-assignment from source. Read more

impl Copy for GenericParamVariance

impl Debug for GenericParamVariance

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

Formats the value using the given formatter. Read more

impl Display for GenericParamVariance

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

Formats the value using the given formatter. Read more

impl Eq for GenericParamVariance

impl Hash for GenericParamVariance

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

Feeds this value into the given Hasher. Read more

1.3.0 · Source§

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

impl PartialEq for GenericParamVariance

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

Equality operator ==. Read more

1.0.0 (const: unstable) · Source§

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

Inequality operator !=. Read more

impl StructuralPartialEq for GenericParamVariance

Auto Trait Implementations§

impl Freeze for GenericParamVariance

impl RefUnwindSafe for GenericParamVariance

impl Send for GenericParamVariance

impl Sync for GenericParamVariance

impl Unpin for GenericParamVariance

impl UnsafeUnpin for GenericParamVariance

impl UnwindSafe for GenericParamVariance

Blanket Implementations§

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

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> AsAny for T
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fn as_any(&self) -> &(dyn Any + 'static)

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

fn type_name(&self) -> &'static str

Gets the type name of self

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

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

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fn equivalent(&self, key: &K) -> bool

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fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more

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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.

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Calls U::from(self).

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

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fn into_ast(self, _a: &A) -> A

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Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more

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fn into_sample(self) -> T

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const ALIGN: usize

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type Init = T

The type for initializers.

unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more

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The inverse inclusion map: attempts to construct self from the equivalent element of its superset. Read more

fn is_in_subset(&self) -> bool

Checks if self is actually part of its subset T (and can be converted to it).

fn to_subset_unchecked(&self) -> SS

Use with care! Same as self.to_subset but without any property checks. Always succeeds.

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