Struct Shape

#[non_exhaustive]
#[repr(C)]
pub struct Shape {
    pub id: ConstTypeId,
    pub layout: ShapeLayout,
    pub vtable: &'static ValueVTable,
    pub def: Def,
    pub type_params: &'static [TypeParam],
    pub doc: &'static [&'static str],
    pub attributes: &'static [ShapeAttribute],
    pub inner: Option<fn() -> &'static Shape>,
}

Schema for reflection of a type

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

id: ConstTypeId

Unique type identifier, provided by the compiler.

layout: ShapeLayout

Size, alignment — enough to allocate a value of this type (but not initialize it.)

vtable: &'static ValueVTable

Function pointers to perform various operations: print the full type name (with generic type parameters), use the Display implementation, the Debug implementation, build a default value, clone, etc.

There are more specific vtables in variants of Def

def: Def

Further definition of the value: details for structs, enums, scalars, options, smart pointers, arrays, slices, tuples, etc.

This typically lists fields (with shapes and offsets), reprs, variants and contains vtables that let you perform other operations, like inserting into a map or fetching a value from a list.

type_params: &'static [TypeParam]

Generic parameters for the shape

doc: &'static [&'static str]

Doc comment lines, collected by facet-derive. Note that they tend to start with a space.

attributes: &'static [ShapeAttribute]

Attributes that can be applied to a shape

inner: Option<fn() -> &'static Shape>

As far as serialization and deserialization goes, we consider that this shape is a wrapper for that shape This is true for “newtypes” like NonZero<u8>, wrappers like Utf8PathBuf, smart pointers like Arc<T>, etc.

When this is set, deserialization takes that into account. For example, facet-json doesn’t expect:

{ “NonZero”: { “value”: 128 } }

It expects just

128

Same for Utf8PathBuf, which is parsed from and serialized to “just a string”.

See Wip’s innermost_shape function (and its support in put).

Implementations

impl Shape

pub const fn is(&'static self, characteristic: Characteristic) -> bool

Checks if a shape has the given characteristic.

pub const fn is_send(&'static self) -> bool

Check if this shape implements the Send trait

pub const fn is_sync(&'static self) -> bool

Check if this shape implements the Sync trait

pub const fn is_copy(&'static self) -> bool

Check if this shape implements the Copy trait

pub const fn is_eq(&'static self) -> bool

Check if this shape implements the Eq trait

pub const fn is_clone(&'static self) -> bool

Check if this shape implements the Clone trait

pub const fn is_display(&'static self) -> bool

Check if this shape implements the Display trait

pub const fn is_debug(&'static self) -> bool

Check if this shape implements the Debug trait

pub const fn is_partial_eq(&'static self) -> bool

Check if this shape implements the PartialEq trait

pub const fn is_partial_ord(&'static self) -> bool

Check if this shape implements the PartialOrd trait

pub const fn is_ord(&'static self) -> bool

Check if this shape implements the Ord trait

pub const fn is_hash(&'static self) -> bool

Check if this shape implements the Hash trait

pub const fn is_default(&'static self) -> bool

Check if this shape implements the Default trait

pub const fn is_from_str(&'static self) -> bool

Check if this shape implements the FromStr trait

pub fn write_type_name( &self, f: &mut Formatter<'_>, opts: TypeNameOpts, ) -> Result<(), Error>

Writes the name of this type to the given formatter

impl Shape

pub const fn builder() -> ShapeBuilder

Returns a builder for shape

pub const fn builder_for_sized<T>() -> ShapeBuilder

Returns a builder for a shape for some type T.

pub fn is_type<Other>(&'static self) -> bool

where Other: Facet<'static>,

Check if this shape is of the given type

pub fn assert_type<Other>(&'static self)

where Other: Facet<'static>,

Assert that this shape is of the given type, panicking if it’s not

pub fn has_deny_unknown_fields_attr(&'static self) -> bool

See ShapeAttribute::DenyUnknownFields

pub fn has_default_attr(&'static self) -> bool

See ShapeAttribute::Default

pub fn get_rename_all_attr(&'static self) -> Option<&'static str>

See ShapeAttribute::RenameAll

impl Shape

pub fn is_shape(&'static self, other: &'static Shape) -> bool

Check if this shape is of the given type

pub fn assert_shape(&'static self, other: &'static Shape)

Assert that this shape is equal to the given shape, panicking if it’s not

impl Shape

pub fn allocate(&self) -> Result<PtrUninit<'static>, UnsizedError>

Heap-allocate a value of this shape

pub unsafe fn deallocate_mut(&self, ptr: PtrMut<'_>) -> Result<(), UnsizedError>

Deallocate a heap-allocated value of this shape

Safety

• ptr must have been allocated using Self::allocate and be aligned for this shape.
• ptr must point to a region that is not already deallocated.

pub unsafe fn deallocate_uninit( &self, ptr: PtrUninit<'static>, ) -> Result<(), UnsizedError>

Deallocate a heap-allocated, uninitialized value of this shape.

Safety

• ptr must have been allocated using Self::allocate (or equivalent) for this shape.
• ptr must not have been already deallocated.
• ptr must be properly aligned for this shape.

Trait Implementations

impl Clone for Shape

fn clone(&self) -> Shape

Returns a copy 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<(), Error>

Formats the value using the given formatter.

impl Display for Shape

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

Formats the value using the given formatter.

impl Hash for Shape

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

where H: Hasher,

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: &Shape) -> 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