Struct wasmtime::FuncType

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pub struct FuncType { /* private fields */ }
Available on crate feature runtime only.
Expand description

The type of a WebAssembly function.

WebAssembly functions can have 0 or more parameters and results.

§Subtyping and Equality

FuncType does not implement Eq, because reference types have a subtyping relationship, and so 99.99% of the time you actually want to check whether one type matches (i.e. is a subtype of) another type. You can use the FuncType::matches and Func::matches_ty methods to perform these types of checks. If, however, you are in that 0.01% scenario where you need to check precise equality between types, you can use the FuncType::eq method.

Implementations§

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impl FuncType

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pub fn new( engine: &Engine, params: impl IntoIterator<Item = ValType>, results: impl IntoIterator<Item = ValType> ) -> FuncType

Creates a new function type from the given parameters and results.

The function type returned will represent a function which takes params as arguments and returns results when it is finished.

The resulting function type will be final and without a supertype.

§Panics

Panics if any parameter or value type is not associated with the given engine.

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pub fn with_finality_and_supertype( engine: &Engine, finality: Finality, supertype: Option<&Self>, params: impl IntoIterator<Item = ValType>, results: impl IntoIterator<Item = ValType> ) -> Result<Self>

Create a new function type with the given finality, supertype, parameter types, and result types.

Returns an error if the supertype is final, or if this function type does not match the supertype.

§Panics

Panics if any parameter or value type is not associated with the given engine.

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pub fn engine(&self) -> &Engine

Get the engine that this function type is associated with.

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pub fn finality(&self) -> Finality

Get the finality of this function type.

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pub fn supertype(&self) -> Option<Self>

Get the supertype of this function type, if any.

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pub fn param(&self, i: usize) -> Option<ValType>

Get the ith parameter type.

Returns None if i is out of bounds.

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pub fn params(&self) -> impl ExactSizeIterator<Item = ValType> + '_

Returns the list of parameter types for this function.

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pub fn result(&self, i: usize) -> Option<ValType>

Get the ith result type.

Returns None if i is out of bounds.

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pub fn results(&self) -> impl ExactSizeIterator<Item = ValType> + '_

Returns the list of result types for this function.

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pub fn matches(&self, other: &FuncType) -> bool

Does this function type match the other function type?

That is, is this function type a subtype of the other function type?

§Panics

Panics if either type is associated with a different engine from the other.

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pub fn eq(a: &FuncType, b: &FuncType) -> bool

Is function type a precisely equal to function type b?

Returns false even if a is a subtype of b or vice versa, if they are not exactly the same function type.

§Panics

Panics if either type is associated with a different engine from the other.

Trait Implementations§

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impl Clone for FuncType

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fn clone(&self) -> FuncType

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 FuncType

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

Formats the value using the given formatter. Read more
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impl Display for FuncType

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

Formats the value using the given formatter. Read more
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impl From<FuncType> for ExternType

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fn from(ty: FuncType) -> ExternType

Converts to this type from the input type.
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impl From<FuncType> for HeapType

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fn from(f: FuncType) -> Self

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

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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

Auto Trait Implementations§

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> 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<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 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<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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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> 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.