Struct Shape

pub struct Shape {
    pub name: NameFn,
    pub typeid: TypeId,
    pub layout: Layout,
    pub innards: Innards,
    pub set_to_default: Option<SetToDefaultFn>,
    pub drop_in_place: Option<DropFn>,
}

Schema for reflection of a type

Fields

name: NameFn

A descriptive name for the type, e.g. u64, or Person

typeid: TypeId

The typeid of the underlying type

layout: Layout

Size, alignment

innards: Innards

Details/contents of the value

set_to_default: Option<SetToDefaultFn>

Set the value at a given address to the default value for this type

drop_in_place: Option<DropFn>

Drop the value at a given address

Safety

This function should be called only for initialized values. It’s the caller’s responsibility to ensure the address points to a valid value.

Implementations

impl Shape

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

Pretty-print this shape, recursively.

impl Shape

pub unsafe fn get_scalar_contents<'a>( &self, ptr: *const u8, ) -> ScalarContents<'a>

Extract the scalar contents from a shape and a pointer

Safety

This function is unsafe because it reads from raw memory. The caller must ensure that:

1. The pointer points to a valid, initialized value of the correct type
2. The memory is properly aligned for the type
3. The memory is not mutated while the returned ScalarContents is in use

pub fn known_fields(&self) -> &'static [Field]

Returns a slice of statically known fields. Fields that are not in there might still be inserted if it’s a dynamic collection.

pub fn field_by_name(&self, name: &str) -> Option<&Field>

Returns a reference to a field with the given name, if it exists

pub fn field_by_index(&self, index: usize) -> Result<&Field, FieldError>

Returns a reference to a field with the given index, if it exists

pub fn dangling(&self) -> NonNull<u8>

Returns a dangling pointer for this shape.

This is useful for zero-sized types (ZSTs) which don’t need actual memory allocation, but still need a properly aligned “some address”.

Safety

This function returns a dangling pointer. It should only be used in contexts where a non-null pointer is required but no actual memory access will occur, such as for ZSTs.

pub fn variants(&self) -> &'static [Variant]

Returns a slice of enum variants, if this shape represents an enum

pub fn variant_by_name(&self, name: &str) -> Option<&Variant>

Returns a reference to a variant with the given name, if it exists

pub fn variant_by_index(&self, index: usize) -> Result<&Variant, VariantError>

Returns a reference to a variant with the given index, if it exists

pub fn enum_repr(&self) -> Option<EnumRepr>

Returns the enum representation, if this shape represents an enum

Trait Implementations

impl Clone for Shape

fn clone(&self) -> Shape

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Shape

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

Formats the value using the given formatter.

impl Display for Shape

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

Formats the value using the given formatter.

impl Hash for Shape

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

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Shape

fn eq(&self, other: &Self) -> 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 Shape

impl Eq for Shape