Struct scale_info::Variant

pub struct Variant<T: Form = MetaForm> {
    pub name: T::String,
    pub fields: Vec<Field<T>>,
    pub index: u8,
    pub docs: Vec<T::String>,
}

A struct enum variant with either named (struct) or unnamed (tuple struct) fields.

Example

enum Operation {
    Zero,
//  ^^^^ this is a unit struct enum variant
    Add(i32, i32),
//  ^^^^^^^^^^^^^ this is a tuple-struct enum variant
    Minus { source: i32 }
//  ^^^^^^^^^^^^^^^^^^^^^ this is a struct enum variant
}

Fields

name: T::String

The name of the variant.

fields: Vec<Field<T>>

The fields of the variant.

index: u8

Index of the variant, used in parity-scale-codec.

The value of this will be, in order of precedence: 1. The explicit index defined by a #[codec(index = N)] attribute. 2. The implicit index from the position of the variant in the enum definition.

docs: Vec<T::String>

Documentation

Implementations

impl<T> Variant<T>where
    T: Form,

pub fn new(
    name: T::String,
    fields: Vec<Field<T>>,
    index: u8,
    docs: Vec<T::String>
) -> Self

Creates a new variant.

impl<T> Variant<T>where
    T: Form,

pub fn name(&self) -> &T::String

Returns the name of the variant.

pub fn fields(&self) -> &[Field<T>]

Returns the fields of the struct variant.

pub fn index(&self) -> u8

Returns the index of the variant.

pub fn docs(&self) -> &[T::String]

Returns the documentation of the variant.

Trait Implementations

impl<T: Clone + Form> Clone for Variant<T>where
    T::String: Clone,

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug + Form> Debug for Variant<T>where
    T::String: Debug,

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

Formats the value using the given formatter.

impl<T: Form> Decode for Variant<T>where
    T::String: Decode,
    Vec<Field<T>>: Decode,
    Vec<T::String>: Decode,

fn decode<__CodecInputEdqy: Input>(
    __codec_input_edqy: &mut __CodecInputEdqy
) -> Result<Self, Error>

Attempt to deserialise the value from input.

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

Attempt to skip the encoded value from input.

fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type.

impl<T: Form> Encode for Variant<T>where
    T::String: Encode,
    Vec<Field<T>>: Encode,
    Vec<T::String>: Encode,

fn encode_to<__CodecOutputEdqy: Output + ?Sized>(
    &self,
    __codec_dest_edqy: &mut __CodecOutputEdqy
)

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.

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

Convert self to an owned vector.

fn using_encoded<R, F>(&self, f: F) -> Rwhere
    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.

impl IntoPortable for Variant

type Output = Variant<PortableForm>

The portable version of Self.

fn into_portable(self, registry: &mut Registry) -> Self::Output

Convert self to the portable form by using the registry for caching.

impl<T: Ord + Form> Ord for Variant<T>where
    T::String: Ord,

fn cmp(&self, other: &Variant<T>) -> Ordering

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

Restrict a value to a certain interval.

impl<T: PartialEq + Form> PartialEq<Variant<T>> for Variant<T>where
    T::String: PartialEq,

fn eq(&self, other: &Variant<T>) -> bool

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

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.

impl<T: PartialOrd + Form> PartialOrd<Variant<T>> for Variant<T>where
    T::String: PartialOrd,

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

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

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

impl<T: Form> EncodeLike<Variant<T>> for Variant<T>where
    T::String: Encode,
    Vec<Field<T>>: Encode,
    Vec<T::String>: Encode,

impl<T: Eq + Form> Eq for Variant<T>where
    T::String: Eq,

impl<T: Form> StructuralEq for Variant<T>

impl<T: Form> StructuralPartialEq for Variant<T>