referrerpolicy=no-referrer-when-downgrade

Struct polkadot_service::runtime_traits::PhantomData

1.0.0 · source ·
pub struct PhantomData<T>
where
    T: ?Sized;
Expand description

Zero-sized type used to mark things that “act like” they own a T.

Adding a PhantomData<T> field to your type tells the compiler that your type acts as though it stores a value of type T, even though it doesn’t really. This information is used when computing certain safety properties.

For a more in-depth explanation of how to use PhantomData<T>, please see the Nomicon.

§A ghastly note 👻👻👻

Though they both have scary names, PhantomData and ‘phantom types’ are related, but not identical. A phantom type parameter is simply a type parameter which is never used. In Rust, this often causes the compiler to complain, and the solution is to add a “dummy” use by way of PhantomData.

§Examples

§Unused lifetime parameters

Perhaps the most common use case for PhantomData is a struct that has an unused lifetime parameter, typically as part of some unsafe code. For example, here is a struct Slice that has two pointers of type *const T, presumably pointing into an array somewhere:

struct Slice<'a, T> {
    start: *const T,
    end: *const T,
}

The intention is that the underlying data is only valid for the lifetime 'a, so Slice should not outlive 'a. However, this intent is not expressed in the code, since there are no uses of the lifetime 'a and hence it is not clear what data it applies to. We can correct this by telling the compiler to act as if the Slice struct contained a reference &'a T:

use std::marker::PhantomData;

struct Slice<'a, T> {
    start: *const T,
    end: *const T,
    phantom: PhantomData<&'a T>,
}

This also in turn infers the lifetime bound T: 'a, indicating that any references in T are valid over the lifetime 'a.

When initializing a Slice you simply provide the value PhantomData for the field phantom:

fn borrow_vec<T>(vec: &Vec<T>) -> Slice<'_, T> {
    let ptr = vec.as_ptr();
    Slice {
        start: ptr,
        end: unsafe { ptr.add(vec.len()) },
        phantom: PhantomData,
    }
}

§Unused type parameters

It sometimes happens that you have unused type parameters which indicate what type of data a struct is “tied” to, even though that data is not actually found in the struct itself. Here is an example where this arises with FFI. The foreign interface uses handles of type *mut () to refer to Rust values of different types. We track the Rust type using a phantom type parameter on the struct ExternalResource which wraps a handle.

use std::marker::PhantomData;
use std::mem;

struct ExternalResource<R> {
   resource_handle: *mut (),
   resource_type: PhantomData<R>,
}

impl<R: ResType> ExternalResource<R> {
    fn new() -> Self {
        let size_of_res = mem::size_of::<R>();
        Self {
            resource_handle: foreign_lib::new(size_of_res),
            resource_type: PhantomData,
        }
    }

    fn do_stuff(&self, param: ParamType) {
        let foreign_params = convert_params(param);
        foreign_lib::do_stuff(self.resource_handle, foreign_params);
    }
}

§Ownership and the drop check

The exact interaction of PhantomData with drop check may change in the future.

Currently, adding a field of type PhantomData<T> indicates that your type owns data of type T in very rare circumstances. This in turn has effects on the Rust compiler’s drop check analysis. For the exact rules, see the drop check documentation.

§Layout

For all T, the following are guaranteed:

  • size_of::<PhantomData<T>>() == 0
  • align_of::<PhantomData<T>>() == 1

Trait Implementations§

§

impl<'a, A> Arbitrary<'a> for PhantomData<A>
where A: Arbitrary<'a>,

§

fn arbitrary(_: &mut Unstructured<'a>) -> Result<PhantomData<A>, Error>

Generate an arbitrary value of Self from the given unstructured data. Read more
§

fn size_hint(_depth: usize) -> (usize, Option<usize>)

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself. Read more
§

fn arbitrary_take_rest(u: Unstructured<'a>) -> Result<Self, Error>

Generate an arbitrary value of Self from the entirety of the given unstructured data. Read more
§

impl<T> AsBytes for PhantomData<T>
where T: ?Sized,

§

fn as_bytes(&self) -> &[u8]

Gets the bytes of this value. Read more
§

fn as_bytes_mut(&mut self) -> &mut [u8]
where Self: FromBytes,

Gets the bytes of this value mutably. Read more
§

fn write_to(&self, bytes: &mut [u8]) -> Option<()>

Writes a copy of self to bytes. Read more
§

fn write_to_prefix(&self, bytes: &mut [u8]) -> Option<()>

Writes a copy of self to the prefix of bytes. Read more
§

fn write_to_suffix(&self, bytes: &mut [u8]) -> Option<()>

Writes a copy of self to the suffix of bytes. Read more
§

impl<T> CanonicalDeserialize for PhantomData<T>
where T: Send + Sync,

§

fn deserialize_with_mode<R>( _reader: R, _compress: Compress, _validate: Validate, ) -> Result<PhantomData<T>, SerializationError>
where R: Read,

The general deserialize method that takes in customization flags.
§

fn deserialize_compressed<R>(reader: R) -> Result<Self, SerializationError>
where R: Read,

§

fn deserialize_compressed_unchecked<R>( reader: R, ) -> Result<Self, SerializationError>
where R: Read,

§

fn deserialize_uncompressed<R>(reader: R) -> Result<Self, SerializationError>
where R: Read,

§

fn deserialize_uncompressed_unchecked<R>( reader: R, ) -> Result<Self, SerializationError>
where R: Read,

§

impl<T> CanonicalSerialize for PhantomData<T>

§

fn serialize_with_mode<W>( &self, _writer: W, _compress: Compress, ) -> Result<(), SerializationError>
where W: Write,

The general serialize method that takes in customization flags.
§

fn serialized_size(&self, _compress: Compress) -> usize

§

fn serialize_compressed<W>(&self, writer: W) -> Result<(), SerializationError>
where W: Write,

§

fn compressed_size(&self) -> usize

§

fn serialize_uncompressed<W>(&self, writer: W) -> Result<(), SerializationError>
where W: Write,

§

fn uncompressed_size(&self) -> usize

1.0.0 · source§

impl<T> Clone for PhantomData<T>
where T: ?Sized,

source§

fn clone(&self) -> PhantomData<T>

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
1.0.0 · source§

impl<T> Debug for PhantomData<T>
where T: ?Sized,

source§

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

Formats the value using the given formatter. Read more
§

impl<'a, T> Decode<'a> for PhantomData<T>
where T: ?Sized,

Dummy implementation for PhantomData which allows deriving implementations on structs with phantom fields.

§

fn decode<R>(_reader: &mut R) -> Result<PhantomData<T>, Error>
where R: Reader<'a>,

Attempt to decode this message using the provided decoder.
§

fn from_der(bytes: &'a [u8]) -> Result<Self, Error>

Parse Self from the provided DER-encoded byte slice.
§

impl<T> Decode for PhantomData<T>

§

fn decode<I>(_input: &mut I) -> Result<PhantomData<T>, Error>
where I: Input,

Attempt to deserialise the value from input.
§

fn decode_into<I>( input: &mut I, dst: &mut MaybeUninit<Self>, ) -> Result<DecodeFinished, Error>
where I: Input,

Attempt to deserialize the value from input into a pre-allocated piece of memory. Read more
§

fn skip<I>(input: &mut I) -> Result<(), Error>
where I: Input,

Attempt to skip the encoded value from input. Read more
§

fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type. Read more
1.0.0 · source§

impl<T> Default for PhantomData<T>
where T: ?Sized,

source§

fn default() -> PhantomData<T>

Returns the “default value” for a type. Read more
§

impl<T> DerOrd for PhantomData<T>

Provide a no-op implementation for PhantomData

§

fn der_cmp(&self, _other: &PhantomData<T>) -> Result<Ordering, Error>

Return an Ordering between self and other when serialized as ASN.1 DER.
source§

impl<'de, T> Deserialize<'de> for PhantomData<T>
where T: ?Sized,

source§

fn deserialize<D>( deserializer: D, ) -> Result<PhantomData<T>, <D as Deserializer<'de>>::Error>
where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more
source§

impl<'de, T> DeserializeSeed<'de> for PhantomData<T>
where T: Deserialize<'de>,

§

type Value = T

The type produced by using this seed.
source§

fn deserialize<D>( self, deserializer: D, ) -> Result<T, <D as Deserializer<'de>>::Error>
where D: Deserializer<'de>,

Equivalent to the more common Deserialize::deserialize method, except with some initial piece of data (the seed) passed in.
§

impl<T> Encode for PhantomData<T>

§

fn encode_to<W>(&self, _dest: &mut W)
where W: Output + ?Sized,

Convert self to a slice and append it to the destination.
§

fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding. Read more
§

fn encode(&self) -> Vec<u8>

Convert self to an owned vector.
§

fn using_encoded<R, F>(&self, f: F) -> R
where F: FnOnce(&[u8]) -> R,

Convert self to a slice and then invoke the given closure with it.
§

fn encoded_size(&self) -> usize

Calculates the encoded size. Read more
§

impl<T> Encode for PhantomData<T>
where T: ?Sized,

Dummy implementation for PhantomData which allows deriving implementations on structs with phantom fields.

§

fn encoded_len(&self) -> Result<Length, Error>

Compute the length of this value in bytes when encoded as ASN.1 DER.
§

fn encode(&self, _writer: &mut impl Writer) -> Result<(), Error>

Encode this value as ASN.1 DER using the provided [Writer].
§

fn encode_to_slice<'a>(&self, buf: &'a mut [u8]) -> Result<&'a [u8], Error>

Encode this value to the provided byte slice, returning a sub-slice containing the encoded message.
§

fn encode_to_vec(&self, buf: &mut Vec<u8>) -> Result<Length, Error>

Encode this message as ASN.1 DER, appending it to the provided byte vector.
§

fn to_der(&self) -> Result<Vec<u8>, Error>

Encode this type as DER, returning a byte vector.
§

impl<T> EncodeAsType for PhantomData<T>

§

fn encode_as_type_to<R>( &self, type_id: <R as TypeResolver>::TypeId, types: &R, out: &mut Vec<u8>, ) -> Result<(), Error>
where R: TypeResolver,

Given some type_id, types, a context and some output target for the SCALE encoded bytes, attempt to SCALE encode the current value into the type given by type_id.
§

fn encode_as_type<R>( &self, type_id: <R as TypeResolver>::TypeId, types: &R, ) -> Result<Vec<u8>, Error>
where R: TypeResolver,

This is a helper function which internally calls [EncodeAsType::encode_as_type_to]. Prefer to implement that instead.
§

impl<T> FromBytes for PhantomData<T>
where T: ?Sized,

§

fn ref_from(bytes: &[u8]) -> Option<&Self>
where Self: Sized,

Interprets the given bytes as a &Self without copying. Read more
§

fn ref_from_prefix(bytes: &[u8]) -> Option<&Self>
where Self: Sized,

Interprets the prefix of the given bytes as a &Self without copying. Read more
§

fn ref_from_suffix(bytes: &[u8]) -> Option<&Self>
where Self: Sized,

Interprets the suffix of the given bytes as a &Self without copying. Read more
§

fn mut_from(bytes: &mut [u8]) -> Option<&mut Self>
where Self: Sized + AsBytes,

Interprets the given bytes as a &mut Self without copying. Read more
§

fn mut_from_prefix(bytes: &mut [u8]) -> Option<&mut Self>
where Self: Sized + AsBytes,

Interprets the prefix of the given bytes as a &mut Self without copying. Read more
§

fn mut_from_suffix(bytes: &mut [u8]) -> Option<&mut Self>
where Self: Sized + AsBytes,

Interprets the suffix of the given bytes as a &mut Self without copying. Read more
§

fn slice_from(bytes: &[u8]) -> Option<&[Self]>
where Self: Sized,

Interprets the given bytes as a &[Self] without copying. Read more
§

fn slice_from_prefix(bytes: &[u8], count: usize) -> Option<(&[Self], &[u8])>
where Self: Sized,

Interprets the prefix of the given bytes as a &[Self] with length equal to count without copying. Read more
§

fn slice_from_suffix(bytes: &[u8], count: usize) -> Option<(&[u8], &[Self])>
where Self: Sized,

Interprets the suffix of the given bytes as a &[Self] with length equal to count without copying. Read more
§

fn mut_slice_from(bytes: &mut [u8]) -> Option<&mut [Self]>
where Self: Sized + AsBytes,

Interprets the given bytes as a &mut [Self] without copying. Read more
§

fn mut_slice_from_prefix( bytes: &mut [u8], count: usize, ) -> Option<(&mut [Self], &mut [u8])>
where Self: Sized + AsBytes,

Interprets the prefix of the given bytes as a &mut [Self] with length equal to count without copying. Read more
§

fn mut_slice_from_suffix( bytes: &mut [u8], count: usize, ) -> Option<(&mut [u8], &mut [Self])>
where Self: Sized + AsBytes,

Interprets the suffix of the given bytes as a &mut [Self] with length equal to count without copying. Read more
§

fn read_from(bytes: &[u8]) -> Option<Self>
where Self: Sized,

Reads a copy of Self from bytes. Read more
§

fn read_from_prefix(bytes: &[u8]) -> Option<Self>
where Self: Sized,

Reads a copy of Self from the prefix of bytes. Read more
§

fn read_from_suffix(bytes: &[u8]) -> Option<Self>
where Self: Sized,

Reads a copy of Self from the suffix of bytes. Read more
§

impl<T> FromZeroes for PhantomData<T>
where T: ?Sized,

§

fn zero(&mut self)

Overwrites self with zeroes. Read more
§

fn new_zeroed() -> Self
where Self: Sized,

Creates an instance of Self from zeroed bytes. Read more
1.0.0 · source§

impl<T> Hash for PhantomData<T>
where T: ?Sized,

source§

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

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<T> IntoVisitor for PhantomData<T>

§

type AnyVisitor<R: TypeResolver> = BasicVisitor<PhantomData<T>, R>

The visitor type used to decode SCALE encoded bytes to Self.
§

fn into_visitor<R>() -> <PhantomData<T> as IntoVisitor>::AnyVisitor<R>
where R: TypeResolver,

A means of obtaining this visitor.
§

impl<T> JsonSchema for PhantomData<T>
where T: ?Sized,

§

fn is_referenceable() -> bool

Whether JSON Schemas generated for this type should be re-used where possible using the $ref keyword. Read more
§

fn schema_name() -> String

The name of the generated JSON Schema. Read more
§

fn json_schema(gen: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type. Read more
§

impl<T> MaxEncodedLen for PhantomData<T>

§

fn max_encoded_len() -> usize

Upper bound, in bytes, of the maximum encoded size of this item.
1.0.0 · source§

impl<T> Ord for PhantomData<T>
where T: ?Sized,

source§

fn cmp(&self, _other: &PhantomData<T>) -> Ordering

This method returns an Ordering between self and other. Read more
1.21.0 · source§

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

Compares and returns the maximum of two values. Read more
1.21.0 · source§

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

Compares and returns the minimum of two values. Read more
1.50.0 · source§

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

Restrict a value to a certain interval. Read more
source§

impl<T> PalletError for PhantomData<T>

source§

const MAX_ENCODED_SIZE: usize = 0usize

The maximum encoded size for the implementing type. Read more
1.0.0 · source§

impl<T> PartialEq for PhantomData<T>
where T: ?Sized,

source§

fn eq(&self, _other: &PhantomData<T>) -> bool

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

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.
1.0.0 · source§

impl<T> PartialOrd for PhantomData<T>
where T: ?Sized,

source§

fn partial_cmp(&self, _other: &PhantomData<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists. Read more
1.0.0 · source§

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

This method tests less than (for self and other) and is used by the < operator. Read more
1.0.0 · source§

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
1.0.0 · source§

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

This method tests greater than (for self and other) and is used by the > operator. Read more
1.0.0 · source§

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
source§

impl<T> Serialize for PhantomData<T>
where T: ?Sized,

source§

fn serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>
where S: Serializer,

Serialize this value into the given Serde serializer. Read more
§

impl<T> TypeInfo for PhantomData<T>

§

type Identity = PhantomData<()>

The type identifying for which type info is provided. Read more
§

fn type_info() -> Type

Returns the static type identifier for Self.
§

impl<T> Valid for PhantomData<T>
where T: Sync,

§

fn check(&self) -> Result<(), SerializationError>

§

fn batch_check<'a>( batch: impl Iterator<Item = &'a Self> + Send, ) -> Result<(), SerializationError>
where Self: 'a,

§

impl<T> ValueOrd for PhantomData<T>

Provide a no-op implementation for PhantomData

§

fn value_cmp(&self, _other: &PhantomData<T>) -> Result<Ordering, Error>

Return an Ordering between value portion of TLV-encoded self and other when serialized as ASN.1 DER.
§

impl<T> Zeroable for PhantomData<T>
where T: ?Sized,

§

fn zeroed() -> Self

§

impl<Z> Zeroize for PhantomData<Z>

PhantomData is always zero sized so provide a [Zeroize] implementation.

§

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.
§

impl<T> ConstEncodedLen for PhantomData<T>
where T: ConstEncodedLen,

1.0.0 · source§

impl<T> Copy for PhantomData<T>
where T: ?Sized,

§

impl<T> EncodeLike for PhantomData<T>

1.0.0 · source§

impl<T> Eq for PhantomData<T>
where T: ?Sized,

source§

impl<T> Freeze for PhantomData<T>
where T: ?Sized,

§

impl<T> Pod for PhantomData<T>
where T: Pod,

source§

impl<T> StructuralPartialEq for PhantomData<T>
where T: ?Sized,

§

impl<T> Unaligned for PhantomData<T>
where T: ?Sized,

§

impl<Z> ZeroizeOnDrop for PhantomData<Z>

[PhantomData is always zero sized so provide a ZeroizeOnDrop implementation.

Auto Trait Implementations§

§

impl<T> RefUnwindSafe for PhantomData<T>
where T: RefUnwindSafe + ?Sized,

§

impl<T> Send for PhantomData<T>
where T: Send + ?Sized,

§

impl<T> Sync for PhantomData<T>
where T: Sync + ?Sized,

§

impl<T> Unpin for PhantomData<T>
where T: Unpin + ?Sized,

§

impl<T> UnwindSafe for PhantomData<T>
where T: UnwindSafe + ?Sized,

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
§

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

§

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

§

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

§

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

§

impl<T> AnySync for T
where T: Any + Send + Sync,

§

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

source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

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

Mutably borrows from an owned value. Read more
§

impl<T> CallHasher for T
where T: Hash + ?Sized,

§

fn get_hash<H, B>(value: &H, build_hasher: &B) -> u64
where H: Hash + ?Sized, B: BuildHasher,

§

impl<T> CanonicalSerializeHashExt for T
where T: CanonicalSerialize,

§

fn hash<H>(&self) -> GenericArray<u8, <H as OutputSizeUser>::OutputSize>
where H: Digest,

§

fn hash_uncompressed<H>( &self, ) -> GenericArray<u8, <H as OutputSizeUser>::OutputSize>
where H: Digest,

§

impl<T> CheckedBitPattern for T
where T: AnyBitPattern,

§

type Bits = T

Self must have the same layout as the specified Bits except for the possible invalid bit patterns being checked during is_valid_bit_pattern.
§

fn is_valid_bit_pattern(_bits: &T) -> bool

If this function returns true, then it must be valid to reinterpret bits as &Self.
source§

impl<T> CheckedConversion for T

source§

fn checked_from<T>(t: T) -> Option<Self>
where Self: TryFrom<T>,

Convert from a value of T into an equivalent instance of Option<Self>. Read more
source§

fn checked_into<T>(self) -> Option<T>
where Self: TryInto<T>,

Consume self to return Some equivalent value of Option<T>. Read more
source§

impl<T> CheckedConversion for T

source§

fn checked_from<T>(t: T) -> Option<Self>
where Self: TryFrom<T>,

Convert from a value of T into an equivalent instance of Option<Self>. Read more
source§

fn checked_into<T>(self) -> Option<T>
where Self: TryInto<T>,

Consume self to return Some equivalent value of Option<T>. Read more
source§

impl<T> Clear for T
where T: Default + Eq + PartialEq,

source§

fn is_clear(&self) -> bool

True iff no bits are set.
source§

fn clear() -> T

Return the value of Self that is clear.
source§

impl<T> Clear for T
where T: Default + Eq + PartialEq,

source§

fn is_clear(&self) -> bool

True iff no bits are set.
source§

fn clear() -> T

Return the value of Self that is clear.
source§

impl<T> CloneToUninit for T
where T: Copy,

source§

unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
source§

impl<T> CloneToUninit for T
where T: Clone,

source§

default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
§

impl<Q, K> Comparable<K> for Q
where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized,

§

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

Compare self to key and return their ordering.
§

impl<T> Conv for T

§

fn conv<T>(self) -> T
where Self: Into<T>,

Converts self into T using Into<T>. Read more
§

impl<T> DecodeAll for T
where T: Decode,

§

fn decode_all(input: &mut &[u8]) -> Result<T, Error>

Decode Self and consume all of the given input data. Read more
§

impl<T> DecodeAsType for T
where T: IntoVisitor,

§

fn decode_as_type_maybe_compact<R>( input: &mut &[u8], type_id: <R as TypeResolver>::TypeId, types: &R, is_compact: bool, ) -> Result<T, Error>
where R: TypeResolver,

§

fn decode_as_type<R>( input: &mut &[u8], type_id: <R as TypeResolver>::TypeId, types: &R, ) -> Result<Self, Error>
where R: TypeResolver,

Given some input bytes, a type_id, and type registry, attempt to decode said bytes into Self. Implementations should modify the &mut reference to the bytes such that any bytes not used in the course of decoding are still pointed to after decoding is complete.
§

impl<T> DecodeLimit for T
where T: Decode,

§

fn decode_all_with_depth_limit( limit: u32, input: &mut &[u8], ) -> Result<T, Error>

Decode Self and consume all of the given input data. Read more
§

fn decode_with_depth_limit<I>(limit: u32, input: &mut I) -> Result<T, Error>
where I: Input,

Decode Self with the given maximum recursion depth and advance input by the number of bytes consumed. Read more
§

impl<T> DecodeWithMetadata for T
where T: DecodeAsType,

§

fn decode_with_metadata( bytes: &mut &[u8], type_id: u32, metadata: &Metadata, ) -> Result<T, Error>

Given some metadata and a type ID, attempt to SCALE decode the provided bytes into Self.
source§

impl<T> DefensiveMax<T> for T
where T: PartialOrd,

source§

fn defensive_max(self, other: T) -> T

Returns the maximum and defensively asserts that other is not larger than self. Read more
source§

fn defensive_strict_max(self, other: T) -> T

Returns the maximum and defensively asserts that other is smaller than self. Read more
source§

impl<T> DefensiveMin<T> for T
where T: PartialOrd,

source§

fn defensive_min(self, other: T) -> T

Returns the minimum and defensively checks that self is not larger than other. Read more
source§

fn defensive_strict_min(self, other: T) -> T

Returns the minimum and defensively checks that self is smaller than other. Read more
source§

impl<T> DynClone for T
where T: Clone,

source§

fn __clone_box(&self, _: Private) -> *mut ()

source§

impl<T> EncodeAs<T> for T
where T: Encode,

source§

fn encode_as(&self) -> Vec<u8>

Convert Self into T, then encode T. Read more
source§

impl<T> EncodeInto for T
where T: Encode,

source§

fn encode_into<T, H>(&self) -> T
where T: AsMut<[u8]> + Default, H: Hasher,

§

impl<T> EncodeWithMetadata for T
where T: EncodeAsType,

§

fn encode_with_metadata( &self, type_id: u32, metadata: &Metadata, bytes: &mut Vec<u8>, ) -> Result<(), Error>

SCALE encode this type to bytes, possibly with the help of metadata.

source§

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

source§

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

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

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

§

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

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

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

§

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

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

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

§

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

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

impl<T> FmtForward for T

§

fn fmt_binary(self) -> FmtBinary<Self>
where Self: Binary,

Causes self to use its Binary implementation when Debug-formatted.
§

fn fmt_display(self) -> FmtDisplay<Self>
where Self: Display,

Causes self to use its Display implementation when Debug-formatted.
§

fn fmt_lower_exp(self) -> FmtLowerExp<Self>
where Self: LowerExp,

Causes self to use its LowerExp implementation when Debug-formatted.
§

fn fmt_lower_hex(self) -> FmtLowerHex<Self>
where Self: LowerHex,

Causes self to use its LowerHex implementation when Debug-formatted.
§

fn fmt_octal(self) -> FmtOctal<Self>
where Self: Octal,

Causes self to use its Octal implementation when Debug-formatted.
§

fn fmt_pointer(self) -> FmtPointer<Self>
where Self: Pointer,

Causes self to use its Pointer implementation when Debug-formatted.
§

fn fmt_upper_exp(self) -> FmtUpperExp<Self>
where Self: UpperExp,

Causes self to use its UpperExp implementation when Debug-formatted.
§

fn fmt_upper_hex(self) -> FmtUpperHex<Self>
where Self: UpperHex,

Causes self to use its UpperHex implementation when Debug-formatted.
§

fn fmt_list(self) -> FmtList<Self>
where &'a Self: for<'a> IntoIterator,

Formats each item in a sequence. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T> FullLeaf for T
where T: Encode + Decode + Clone + PartialEq + Debug,

source§

fn using_encoded<R, F>(&self, f: F, _compact: bool) -> R
where F: FnOnce(&[u8]) -> R,

Encode the leaf either in its full or compact form. Read more
source§

impl<T> Hashable for T
where T: Codec,

source§

fn blake2_128(&self) -> [u8; 16]

source§

fn blake2_256(&self) -> [u8; 32]

source§

fn blake2_128_concat(&self) -> Vec<u8>

source§

fn twox_128(&self) -> [u8; 16]

source§

fn twox_256(&self) -> [u8; 32]

source§

fn twox_64_concat(&self) -> Vec<u8>

source§

fn identity(&self) -> Vec<u8>

§

impl<T> Instrument for T

§

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

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

impl<T> Instrument for T

source§

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

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
source§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

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

source§

fn into(self) -> U

Calls U::from(self).

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

source§

impl<T> IntoEither for T

source§

fn into_either(self, into_left: bool) -> Either<Self, Self>

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
source§

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

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
source§

impl<T, U> IntoKey<U> for T
where U: FromKey<T>,

source§

fn into_key(self) -> U

§

impl<Src, Dest> IntoTuple<Dest> for Src
where Dest: FromTuple<Src>,

§

fn into_tuple(self) -> Dest

source§

impl<T> IsType<T> for T

source§

fn from_ref(t: &T) -> &T

Cast reference.
source§

fn into_ref(&self) -> &T

Cast reference.
source§

fn from_mut(t: &mut T) -> &mut T

Cast mutable reference.
source§

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

Cast mutable reference.
source§

impl<T, Outer> IsWrappedBy<Outer> for T
where Outer: AsRef<T> + AsMut<T> + From<T>, T: From<Outer>,

source§

fn from_ref(outer: &Outer) -> &T

Get a reference to the inner from the outer.

source§

fn from_mut(outer: &mut Outer) -> &mut T

Get a mutable reference to the inner from the outer.

source§

impl<T, Outer> IsWrappedBy<Outer> for T
where Outer: AsRef<T> + AsMut<T> + From<T>, T: From<Outer>,

source§

fn from_ref(outer: &Outer) -> &T

Get a reference to the inner from the outer.

source§

fn from_mut(outer: &mut Outer) -> &mut T

Get a mutable reference to the inner from the outer.

§

impl<T> KeyedVec for T
where T: Codec,

§

fn to_keyed_vec(&self, prepend_key: &[u8]) -> Vec<u8>

Return an encoding of Self prepended by given slice.
§

impl<T> Pipe for T
where T: ?Sized,

§

fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> R
where Self: Sized,

Pipes by value. This is generally the method you want to use. Read more
§

fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> R
where R: 'a,

Borrows self and passes that borrow into the pipe function. Read more
§

fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R
where R: 'a,

Mutably borrows self and passes that borrow into the pipe function. Read more
§

fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R
where Self: Borrow<B>, B: 'a + ?Sized, R: 'a,

Borrows self, then passes self.borrow() into the pipe function. Read more
§

fn pipe_borrow_mut<'a, B, R>( &'a mut self, func: impl FnOnce(&'a mut B) -> R, ) -> R
where Self: BorrowMut<B>, B: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.borrow_mut() into the pipe function. Read more
§

fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R
where Self: AsRef<U>, U: 'a + ?Sized, R: 'a,

Borrows self, then passes self.as_ref() into the pipe function.
§

fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R
where Self: AsMut<U>, U: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.as_mut() into the pipe function.
§

fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R
where Self: Deref<Target = T>, T: 'a + ?Sized, R: 'a,

Borrows self, then passes self.deref() into the pipe function.
§

fn pipe_deref_mut<'a, T, R>( &'a mut self, func: impl FnOnce(&'a mut T) -> R, ) -> R
where Self: DerefMut<Target = T> + Deref, T: 'a + ?Sized, R: 'a,

Mutably borrows self, then passes self.deref_mut() into the pipe function.
§

impl<T> Pointable for T

§

const ALIGN: usize = _

The alignment of pointer.
§

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
§

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

Mutably dereferences the given pointer. Read more
§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
source§

impl<T> Same for T

§

type Output = T

Should always be Self
source§

impl<T> SaturatedConversion for T

source§

fn saturated_from<T>(t: T) -> Self
where Self: UniqueSaturatedFrom<T>,

Convert from a value of T into an equivalent instance of Self. Read more
source§

fn saturated_into<T>(self) -> T
where Self: UniqueSaturatedInto<T>,

Consume self to return an equivalent value of T. Read more
source§

impl<T> SaturatedConversion for T

source§

fn saturated_from<T>(t: T) -> Self
where Self: UniqueSaturatedFrom<T>,

Convert from a value of T into an equivalent instance of Self. Read more
source§

fn saturated_into<T>(self) -> T
where Self: UniqueSaturatedInto<T>,

Consume self to return an equivalent value of T. Read more
§

impl<SS, SP> SupersetOf<SS> for SP
where SS: SubsetOf<SP>,

§

fn to_subset(&self) -> Option<SS>

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.
§

fn from_subset(element: &SS) -> SP

The inclusion map: converts self to the equivalent element of its superset.
§

impl<T> Tap for T

§

fn tap(self, func: impl FnOnce(&Self)) -> Self

Immutable access to a value. Read more
§

fn tap_mut(self, func: impl FnOnce(&mut Self)) -> Self

Mutable access to a value. Read more
§

fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self
where Self: Borrow<B>, B: ?Sized,

Immutable access to the Borrow<B> of a value. Read more
§

fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self
where Self: BorrowMut<B>, B: ?Sized,

Mutable access to the BorrowMut<B> of a value. Read more
§

fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self
where Self: AsRef<R>, R: ?Sized,

Immutable access to the AsRef<R> view of a value. Read more
§

fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self
where Self: AsMut<R>, R: ?Sized,

Mutable access to the AsMut<R> view of a value. Read more
§

fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self
where Self: Deref<Target = T>, T: ?Sized,

Immutable access to the Deref::Target of a value. Read more
§

fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self
where Self: DerefMut<Target = T> + Deref, T: ?Sized,

Mutable access to the Deref::Target of a value. Read more
§

fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self

Calls .tap() only in debug builds, and is erased in release builds.
§

fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self

Calls .tap_mut() only in debug builds, and is erased in release builds.
§

fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self
where Self: Borrow<B>, B: ?Sized,

Calls .tap_borrow() only in debug builds, and is erased in release builds.
§

fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self
where Self: BorrowMut<B>, B: ?Sized,

Calls .tap_borrow_mut() only in debug builds, and is erased in release builds.
§

fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self
where Self: AsRef<R>, R: ?Sized,

Calls .tap_ref() only in debug builds, and is erased in release builds.
§

fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self
where Self: AsMut<R>, R: ?Sized,

Calls .tap_ref_mut() only in debug builds, and is erased in release builds.
§

fn tap_deref_dbg<T>(self, func: impl FnOnce(&T)) -> Self
where Self: Deref<Target = T>, T: ?Sized,

Calls .tap_deref() only in debug builds, and is erased in release builds.
§

fn tap_deref_mut_dbg<T>(self, func: impl FnOnce(&mut T)) -> Self
where Self: DerefMut<Target = T> + Deref, T: ?Sized,

Calls .tap_deref_mut() only in debug builds, and is erased in release builds.
source§

impl<T> ToOwned for T
where T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
§

impl<T> TryConv for T

§

fn try_conv<T>(self) -> Result<T, Self::Error>
where Self: TryInto<T>,

Attempts to convert self into T using TryInto<T>. Read more
source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

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

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
source§

impl<T, U> TryIntoKey<U> for T
where U: TryFromKey<T>,

§

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

source§

fn try_into_key(self) -> Result<U, <U as TryFromKey<T>>::Error>

source§

impl<S, T> UncheckedInto<T> for S
where T: UncheckedFrom<S>,

source§

fn unchecked_into(self) -> T

The counterpart to unchecked_from.
source§

impl<S, T> UncheckedInto<T> for S
where T: UncheckedFrom<S>,

source§

fn unchecked_into(self) -> T

The counterpart to unchecked_from.
source§

impl<T, S> UniqueSaturatedInto<T> for S
where T: Bounded, S: TryInto<T>,

source§

fn unique_saturated_into(self) -> T

Consume self to return an equivalent value of T.
source§

impl<T, S> UniqueSaturatedInto<T> for S
where T: Bounded, S: TryInto<T>,

source§

fn unique_saturated_into(self) -> T

Consume self to return an equivalent value of T.
§

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

§

fn vzip(self) -> V

§

impl<T> WithSubscriber for T

§

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
§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more
source§

impl<T> WithSubscriber for T

source§

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
source§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
§

impl<T> AnyBitPattern for T
where T: Pod,

source§

impl<T> AssetId for T
where T: FullCodec + Clone + Eq + PartialEq + Debug + TypeInfo + MaxEncodedLen,

§

impl<S> Codec for S
where S: Decode + Encode,

§

impl<T> DecodeOwned for T
where T: for<'a> Decode<'a>,

source§

impl<T> DeserializeOwned for T
where T: for<'de> Deserialize<'de>,

§

impl<T> EncodeLike<&&T> for T
where T: Encode,

§

impl<T> EncodeLike<&T> for T
where T: Encode,

§

impl<T> EncodeLike<&mut T> for T
where T: Encode,

§

impl<T> EncodeLike<Arc<T>> for T
where T: Encode,

§

impl<T> EncodeLike<Box<T>> for T
where T: Encode,

§

impl<'a, T> EncodeLike<Cow<'a, T>> for T
where T: ToOwned + Encode,

§

impl<T> EncodeLike<Rc<T>> for T
where T: Encode,

source§

impl<T> ExHashT for T
where T: Hash + Eq + Debug + Clone + Send + Sync + 'static,

§

impl<S> FullCodec for S
where S: Decode + FullEncode,

§

impl<S> FullEncode for S
where S: Encode + EncodeLike,

source§

impl<T> Hash for T
where T: Send + Sync + Eq + PartialEq + Clone + Default + Debug + Codec + Hash + 'static,

source§

impl<T> IdentifierT for T
where T: Clone + Eq + Ord + Debug + Codec,

§

impl<T> JsonSchemaMaybe for T

§

impl<T> MaybeDebug for T
where T: Debug,

source§

impl<T> MaybeHash for T
where T: Hash,

source§

impl<T> MaybeHash for T
where T: Hash,

source§

impl<T> MaybeHash for T
where T: Hash,

source§

impl<T> MaybeHash for T
where T: Hash,

source§

impl<T> MaybeRefUnwindSafe for T
where T: RefUnwindSafe,

source§

impl<T> MaybeRefUnwindSafe for T
where T: RefUnwindSafe,

source§

impl<T> MaybeRefUnwindSafe for T
where T: RefUnwindSafe,

§

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

source§

impl<T> MaybeSerialize for T
where T: Serialize,

source§

impl<T> MaybeSerialize for T
where T: Serialize,

source§

impl<T> MaybeSerializeDeserialize for T

source§

impl<T> MaybeSerializeDeserialize for T

source§

impl<T> Member for T
where T: Send + Sync + Debug + Eq + PartialEq + Clone + 'static,

source§

impl<T> Member for T
where T: Send + Sync + Debug + Eq + PartialEq + Clone + 'static,

§

impl<T> NoUninit for T
where T: Pod,

source§

impl<T> Parameter for T
where T: Codec + EncodeLike + Clone + Eq + Debug + TypeInfo,

source§

impl<T> RuleType for T
where T: Copy + Debug + Eq + Hash + Ord,

source§

impl<T> Scalar for T
where T: 'static + Clone + PartialEq + Debug,

§

impl<T> Sequence for T
where T: Eq + Hash,

§

impl<T> StaticTypeInfo for T
where T: TypeInfo + 'static,

§

impl<K> SubstreamSetKey for K
where K: Hash + Unpin + Debug + PartialEq + Eq + Copy,

§

impl<T> TypeId for T
where T: Clone + Debug + Default,