pub enum CowArc<'a, T>
where T: 'static + ?Sized,
{ Borrowed(&'a T), Static(&'static T), Owned(Arc<T>), }
Expand description

Much like a Cow, but owned values are Arc-ed to make clones cheap. This should be used for values that are cloned for use across threads and change rarely (if ever).

This also makes an opinionated tradeoff by adding a CowArc::Static and implementing [From<&'static T>] instead of [From<'a T>]. This preserves the static context and prevents conversion to CowArc::Owned in cases where a reference is known to be static. This is an optimization that prevents allocations and atomic ref-counting.

This means that static references should prefer From::from or CowArc::Static and non-static references must use CowArc::Borrowed.

Variants§

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Borrowed(&'a T)

A borrowed value

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Static(&'static T)

A static value reference. This exists to avoid conversion to CowArc::Owned in cases where a reference is known to be static. This is an optimization that prevents allocations and atomic ref-counting.

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Owned(Arc<T>)

An owned Arc-ed value

Implementations§

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impl<'a, T> CowArc<'a, T>
where &'a T: Into<Arc<T>>, T: ?Sized,

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pub fn into_owned(self) -> CowArc<'static, T>

Converts this into an “owned” value. If internally a value is borrowed, it will be cloned into an “owned Arc”. If it is already a CowArc::Owned or a CowArc::Static, it will remain unchanged.

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pub fn clone_owned(&self) -> CowArc<'static, T>

Clones into an owned [CowArc<'static>]. If internally a value is borrowed, it will be cloned into an “owned Arc”. If it is already a CowArc::Owned or CowArc::Static, the value will be cloned. This is equivalent to .clone().into_owned().

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impl<'a, T> AsRef<T> for CowArc<'a, T>
where T: ?Sized,

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fn as_ref(&self) -> &T

Converts this type into a shared reference of the (usually inferred) input type.
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impl<'a, T> Borrow<T> for CowArc<'a, T>
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<'a, T> Clone for CowArc<'a, T>
where T: ?Sized,

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fn clone(&self) -> CowArc<'a, T>

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<'a, T> Debug for CowArc<'a, T>
where T: Debug + ?Sized,

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

Formats the value using the given formatter. Read more
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impl Default for CowArc<'static, Path>

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fn default() -> CowArc<'static, Path>

Returns the “default value” for a type. Read more
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impl Default for CowArc<'static, str>

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fn default() -> CowArc<'static, str>

Returns the “default value” for a type. Read more
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impl<'a, T> Deref for CowArc<'a, T>
where T: ?Sized,

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type Target = T

The resulting type after dereferencing.
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fn deref(&self) -> &<CowArc<'a, T> as Deref>::Target

Dereferences the value.
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impl<'a, T> Display for CowArc<'a, T>
where T: Display + ?Sized,

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

Formats the value using the given formatter. Read more
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impl<'a> From<&'a String> for CowArc<'a, str>

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fn from(value: &'a String) -> CowArc<'a, str>

Converts to this type from the input type.
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impl<T> From<&'static T> for CowArc<'static, T>
where T: ?Sized,

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fn from(value: &'static T) -> CowArc<'static, T>

Converts to this type from the input type.
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impl From<&'static str> for CowArc<'static, Path>

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fn from(value: &'static str) -> CowArc<'static, Path>

Converts to this type from the input type.
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impl From<PathBuf> for CowArc<'static, Path>

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fn from(value: PathBuf) -> CowArc<'static, Path>

Converts to this type from the input type.
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impl From<String> for CowArc<'static, str>

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fn from(value: String) -> CowArc<'static, str>

Converts to this type from the input type.
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impl<'a, T> Hash for CowArc<'a, T>
where T: Hash + ?Sized,

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

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<'a, T> Ord for CowArc<'a, T>
where T: Ord + ?Sized,

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fn cmp(&self, other: &CowArc<'a, T>) -> Ordering

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

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

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

Restrict a value to a certain interval. Read more
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impl<'a, T> PartialEq for CowArc<'a, T>
where T: PartialEq + ?Sized,

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fn eq(&self, other: &CowArc<'a, T>) -> 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<'a, T> PartialOrd for CowArc<'a, T>
where T: PartialOrd + ?Sized,

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fn partial_cmp(&self, other: &CowArc<'a, T>) -> 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<'a, T> Eq for CowArc<'a, T>
where T: PartialEq + ?Sized,

Auto Trait Implementations§

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impl<'a, T: ?Sized> RefUnwindSafe for CowArc<'a, T>
where T: RefUnwindSafe,

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impl<'a, T: ?Sized> Send for CowArc<'a, T>
where T: Send + Sync,

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impl<'a, T: ?Sized> Sync for CowArc<'a, T>
where T: Send + Sync,

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impl<'a, T: ?Sized> Unpin for CowArc<'a, T>

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impl<'a, T: ?Sized> UnwindSafe for CowArc<'a, T>
where T: RefUnwindSafe,

Blanket Implementations§

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impl<T> Any for T
where 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, U> AsBindGroupShaderType<U> for T
where U: ShaderType, &'a T: for<'a> Into<U>,

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fn as_bind_group_shader_type(&self, _images: &RenderAssets<Image>) -> U

Return the T ShaderType for self. When used in AsBindGroup derives, it is safe to assume that all images in self exist.
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impl<T> Borrow<T> for T
where 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 T
where 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<Q, K> Comparable<K> for Q
where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized,

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fn compare(&self, key: &K) -> Ordering

Compare self to key and return their ordering.
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impl<T> Downcast<T> for T

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fn downcast(&self) -> &T

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impl<T> Downcast for T
where T: Any,

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fn into_any(self: Box<T>) -> Box<dyn Any>

Convert Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can then be further downcast into Box<ConcreteType> where ConcreteType implements Trait.
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fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.
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fn as_any(&self) -> &(dyn Any + 'static)

Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.
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fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Convert &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s.
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impl<T> DowncastSync for T
where T: Any + Send + Sync,

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fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Send + Sync>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait.
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impl<T> DynEq for T
where T: Any + Eq,

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

Casts the type to dyn Any.
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fn dyn_eq(&self, other: &(dyn DynEq + 'static)) -> bool

This method tests for self and other values to be equal. Read more
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impl<T> DynHash for T
where T: DynEq + Hash,

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fn as_dyn_eq(&self) -> &(dyn DynEq + 'static)

Casts the type to dyn Any.
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fn dyn_hash(&self, state: &mut dyn Hasher)

Feeds this value into the given Hasher.
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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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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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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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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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<S> FromSample<S> for S

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fn from_sample_(s: S) -> S

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impl<T> FromWorld for T
where T: Default,

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fn from_world(_world: &mut World) -> T

Creates Self using data from the given World.
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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where 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<S, T> ParallelSlice<T> for S
where T: Sync, S: AsRef<[T]>,

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fn par_chunk_map<F, R>( &self, task_pool: &TaskPool, chunk_size: usize, f: F ) -> Vec<R>
where F: Fn(&[T]) -> R + Send + Sync, R: Send + 'static,

Splits the slice in chunks of size chunks_size or less and maps the chunks in parallel across the provided task_pool. One task is spawned in the task pool for every chunk. Read more
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fn par_splat_map<F, R>( &self, task_pool: &TaskPool, max_tasks: Option<usize>, f: F ) -> Vec<R>
where F: Fn(&[T]) -> R + Send + Sync, R: Send + 'static,

Splits the slice into a maximum of max_tasks chunks, and maps the chunks in parallel across the provided task_pool. One task is spawned in the task pool for every chunk. Read more
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impl<T> ToOwned for T
where 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> ToSample<U> for T
where U: FromSample<T>,

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fn to_sample_(self) -> U

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impl<T> ToSmolStr for T
where T: Display + ?Sized,

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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where 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 T
where 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.
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impl<T> TypeData for T
where T: 'static + Send + Sync + Clone,

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impl<T> Upcast<T> for T

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fn upcast(&self) -> Option<&T>

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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
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impl<S, T> Duplex<S> for T
where T: FromSample<S> + ToSample<S>,

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impl<T> Settings for T
where T: 'static + Send + Sync,

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impl<T> WasmNotSend for T
where T: Send,

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impl<T> WasmNotSendSync for T

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impl<T> WasmNotSync for T
where T: Sync,