Trait Facet

pub unsafe trait Facet: Sized {
    const SHAPE: &'static Shape;
    const ARCHETYPE: Self;

    // Provided method
    fn type_eq<Other: Facet>() -> bool { ... }
}

Allows querying the Shape of a type, which in turn lets us inspect any fields, build a value of this type progressively, etc.

Safety

If you implement this wrong, all the safe abstractions in facet-peek, facet-poke, all the serializers, deserializers, the entire ecosystem is unsafe.

You’re responsible for describing the type layout properly, and annotating all the invariants.

Required Associated Constants

const SHAPE: &'static Shape

The shape of this type

const ARCHETYPE: Self

An instance of this type — which doesn’t have to be valid, but it has to “not be UB”. We never actually read from it, or even actually use it for dynamic dispatch, we only use it for inference tricks.

Provided Methods

fn type_eq<Other: Facet>() -> bool

Returns true if the type of self is equal to the type of other

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl Facet for &str

const ARCHETYPE: Self = ""

const SHAPE: &'static Shape

impl Facet for Cow<'_, str>

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl Facet for bool

const ARCHETYPE: Self = false

const SHAPE: &'static Shape

impl Facet for f32

const ARCHETYPE: Self = 0f32

const SHAPE: &'static Shape

impl Facet for f64

const ARCHETYPE: Self = 0f64

const SHAPE: &'static Shape

impl Facet for i8

const ARCHETYPE: Self = 0i8

const SHAPE: &'static Shape

impl Facet for i16

const ARCHETYPE: Self = 0i16

const SHAPE: &'static Shape

impl Facet for i32

const ARCHETYPE: Self = 0i32

const SHAPE: &'static Shape

impl Facet for i64

const ARCHETYPE: Self = 0i64

const SHAPE: &'static Shape

impl Facet for i128

const ARCHETYPE: Self = 0i128

const SHAPE: &'static Shape

impl Facet for u8

const ARCHETYPE: Self = 0u8

const SHAPE: &'static Shape

impl Facet for u16

const ARCHETYPE: Self = 0u16

const SHAPE: &'static Shape

impl Facet for u32

const ARCHETYPE: Self = 0u32

const SHAPE: &'static Shape

impl Facet for u64

const ARCHETYPE: Self = 0u64

const SHAPE: &'static Shape

impl Facet for u128

const ARCHETYPE: Self = 0u128

const SHAPE: &'static Shape

impl Facet for ()

const ARCHETYPE: Self = ()

const SHAPE: &'static Shape

impl Facet for String

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl Facet for RandomState

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<K, V, S> Facet for HashMap<K, V, S>

where K: Facet + Eq + Hash + 'static, V: Facet + 'static, S: Facet + Default,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0> Facet for (T0,)

where T0: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1> Facet for (T0, T1)

where T0: Facet, T1: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2> Facet for (T0, T1, T2)

where T0: Facet, T1: Facet, T2: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3> Facet for (T0, T1, T2, T3)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4> Facet for (T0, T1, T2, T3, T4)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5> Facet for (T0, T1, T2, T3, T4, T5)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5, T6> Facet for (T0, T1, T2, T3, T4, T5, T6)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet, T6: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5, T6, T7> Facet for (T0, T1, T2, T3, T4, T5, T6, T7)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet, T6: Facet, T7: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8> Facet for (T0, T1, T2, T3, T4, T5, T6, T7, T8)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet, T6: Facet, T7: Facet, T8: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9> Facet for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet, T6: Facet, T7: Facet, T8: Facet, T9: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> Facet for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet, T6: Facet, T7: Facet, T8: Facet, T9: Facet, T10: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> Facet for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)

where T0: Facet, T1: Facet, T2: Facet, T3: Facet, T4: Facet, T5: Facet, T6: Facet, T7: Facet, T8: Facet, T9: Facet, T10: Facet, T11: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T> Facet for &[T]

where T: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T> Facet for [T; 1]

where T: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

impl<T> Facet for Vec<T>

where T: Facet,

const ARCHETYPE: Self

const SHAPE: &'static Shape

Implementors