Enum TypeMeta 

pub enum TypeMeta {
    Static {
        size: usize,
        zero_copy: bool,
    },
    Dynamic,
}

Indicates what kind of assumptions can be made when encoding or decoding a type.

Readers and writers may use this to optimize their behavior.

Variants

Static

The type has a statically known serialized size.

Specifying this variant can have significant performance benefits, as it can allow writers to prefetch larger chunks of memory such that subsequent read/write operations in those chunks can be performed at once without intermediate bounds checks.

Specifying this variant incorrectly will almost certainly result in a panic at runtime.

Take care not to specify this on variable length types, like Vec or String, as their serialized size will vary based on their length.

Fields

size: usize

The static serialized size of the type.

zero_copy: bool

Whether the type is eligible for zero-copy encoding/decoding.

This indicates that the type has no invalid bit patterns, no layout requirements, no endianness checks, etc. This is a very strong claim that should be used judiciously.

Specifying this incorrectly may trigger UB.

Dynamic

The type has a dynamic size, and no optimizations can be made.

Trait Implementations

impl Clone for TypeMeta

fn clone(&self) -> TypeMeta

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TypeMeta

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

Formats the value using the given formatter.

impl PartialEq for TypeMeta

fn eq(&self, other: &TypeMeta) -> 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 Copy for TypeMeta

impl Eq for TypeMeta

impl StructuralPartialEq for TypeMeta