Enum SumStaticType

pub enum SumStaticType<Type = (), const N: usize = 0>
where
    Type: Delimited,
{
    None,
    Some(Type),
    Many([Type; N]),
}

A statically shaped representation of field cardinality.

SumStaticType encodes the possible shapes of a field:

• absence (None)
• a single value (Some)
• multiple values (Many)

Context

In the virtual field system:

• VirtualStaticField defines fields whose structure is fully determined at compile time
• SumStaticType provides a matching concrete representation

Representation Model

The Many variant is backed by a fixed-size array ([Type; N]), giving it array-like semantics:

• size is fixed at compile time
• no resizing or allocation
• capacity is encoded directly in the type

This makes SumStaticType suitable for:

• compile-time enforced layouts
• fixed schemas
• zero-overhead representations

Variants

• None: no value
• Some(Type): exactly one value
• Many([Type; N]): fixed-size collection with array semantics

Type Parameters

• Type: element type
• N: compile-time capacity

Key Property

This is a fully determined representation using array semantics, where both cardinality and capacity are encoded directly in the type.

Default Generics

• Type = (): no meaningful value (unit type)
• N = 0: zero-sized array, Many holds no elements

Together, this yields a no-op, zero-sized representation, useful as a placeholder in generic contexts.

Variants

None

Some(Type)

Many([Type; N])

Trait Implementations

impl<Type, const N: usize> Clone for SumStaticType<Type, N>

where Type: Delimited + Clone,

fn clone(&self) -> SumStaticType<Type, N>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Type, const N: usize> Debug for SumStaticType<Type, N>

where Type: Delimited + Debug,

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

Formats the value using the given formatter.

impl<Type, const N: usize> Decode for SumStaticType<Type, N>

where Type: Delimited + Decode, [Type; N]: Decode,

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

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.

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<Type, const N: usize> Default for SumStaticType<Type, N>

where Type: Delimited,

fn default() -> SumStaticType<Type, N>

Returns the “default value” for a type.

impl<Type, const N: usize> Encode for SumStaticType<Type, N>

where Type: Delimited + Encode, [Type; N]: Encode,

fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding.

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

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

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.

impl<Type, const N: usize> FromTag<[Type; N], ManyTag> for SumStaticType<Type, N>

where Type: Delimited,

fn from_tag(t: [Type; N]) -> Self

impl<Type, const N: usize> FromTag<(), NoneTag> for SumStaticType<Type, N>

where Type: Delimited,

fn from_tag(_t: ()) -> Self

impl<Type, const N: usize> FromTag<Type, SomeTag> for SumStaticType<Type, N>

where Type: Delimited,

fn from_tag(t: Type) -> Self

impl<Type, const N: usize> MaxEncodedLen for SumStaticType<Type, N>

where Type: Delimited + MaxEncodedLen, [Type; N]: MaxEncodedLen,

fn max_encoded_len() -> usize

Upper bound, in bytes, of the maximum encoded size of this item.

impl<Type, const N: usize> PartialEq for SumStaticType<Type, N>

where Type: Delimited + PartialEq,

fn eq(&self, other: &SumStaticType<Type, N>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<Type, const N: usize> TryIntoTag<[Type; N], ManyTag> for SumStaticType<Type, N>

where Type: Delimited,

type Error = ()

fn try_into_tag(self) -> Result<[Type; N], Self::Error>

impl<Type, const N: usize> TryIntoTag<(), NoneTag> for SumStaticType<Type, N>

where Type: Delimited,

type Error = ()

fn try_into_tag(self) -> Result<(), Self::Error>

impl<Type, const N: usize> TryIntoTag<Type, SomeTag> for SumStaticType<Type, N>

where Type: Delimited,

type Error = ()

fn try_into_tag(self) -> Result<Type, Self::Error>

impl<Type, const N: usize> TypeInfo for SumStaticType<Type, N>

where Type: Delimited + TypeInfo + 'static, [Type; N]: TypeInfo + 'static,

type Identity = SumStaticType<Type, N>

The type identifying for which type info is provided.

fn type_info() -> Type

Returns the static type identifier for Self.

impl<Type, const N: usize> DecodeWithMemTracking for SumStaticType<Type, N>

where Type: Delimited + DecodeWithMemTracking, [Type; N]: DecodeWithMemTracking,

impl<Type, const N: usize> EncodeLike for SumStaticType<Type, N>

where Type: Delimited + Encode, [Type; N]: Encode,

impl<Type, const N: usize> Eq for SumStaticType<Type, N>

where Type: Delimited + Eq,

impl<Type, const N: usize> StructuralPartialEq for SumStaticType<Type, N>

where Type: Delimited,