Crate facet_core

Expand description

Defines the Facet trait and implements it for a lot (a LOT) of builtin types.

This crate is foundational to facet’s reflection capabilities, providing the type system that enables runtime type manipulation.

§Sponsors

Thanks to all individual sponsors:

…along with corporate sponsors:

…without whom this work could not exist.

§Special thanks

The facet logo was drawn by Misiasart.

§License

Licensed under either of:

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Modules§

specialization: Auto-deref specialization helpers for the Facet reflection system

Macros§

bitflags: Defines a bitflags struct with the given flags.
builder_def: Generates a builder struct and basic setter methods.
type_ops_direct: Creates a TypeOpsDirect for a type by specifying which traits it implements.
vtable_direct: Creates a VTableDirect for a type by specifying which traits it implements.
vtable_indirect: Creates a VTableIndirect for generic container types by specifying which traits it implements.

Structs§

ArrayDef: Fields for array types
ArrayType: Describes a fixed-size array ([T; N])
ArrayVTable: Virtual table for an array
ArrayVTableBuilder: Builder for the vtable
Attr: An attribute attaches metadata to a container or a field
ConstTypeId: TypeId equivalent usable in const contexts.
DefArrayBuilder: Builder that produces Def::Array(...).
DefListBuilder: Builder that produces Def::List(...).
DefMapBuilder: Builder that produces Def::Map(...).
DefOptionBuilder: Builder that produces Def::Option(...).
DefResultBuilder: Builder that produces Def::Result(...).
DefSetBuilder: Builder that produces Def::Set(...).
DynamicValueDef: Definition for dynamic value types.
DynamicValueVTable: Virtual table for dynamic value types.
EnumType: Fields for enum types
EnumTypeBuilder: Builder for constructing EnumType instances in const contexts.
Field: Describes a field in a struct or tuple
FieldBuilder: Builder for constructing Field instances in const contexts.
FieldFlags: Bit flags for common field attributes.
FunctionPointerDef: Common fields for function pointer types
HashProxy: A proxy type that wraps &mut dyn Hasher and implements Hasher.
IterVTable: VTable for an iterator
ListDef: Fields for list types
ListTypeOps: Per-type list operations that must be monomorphized.
ListTypeOpsBuilder: Builder for ListTypeOps.
ListVTable: Virtual table for shareable list operations.
ListVTableBuilder: Builder for the vtable
LockGuardVTable: Functions for manipulating a guard
LockResult: Type-erased result of locking a mutex-like pointer
MapDef: Fields for map types
MapVTable: Virtual table for a Map<K, V>
MapVTableBuilder: Builder for the vtable
MarkerTraits: Bitflags tracking implementation of Rust’s marker/auto traits.
NativeWidePtr: A wide pointer in native platform layout.
NdArrayDef: Fields for n-dimensional array types
NdArrayVTable: Virtual table for a n-dimensional array type (like Matrix<T>, Tensor<T>, etc.)
Opaque: Wrapper for struct fields whose types we don’t want to expose. Prevents direct access while preserving layout.
OptionDef: Describes an Option — including a vtable to query and alter its state, and the inner shape (the T in Option<T>).
OptionVTable: Virtual table for Option<T>
OptionVTableBuilder: Builder for the vtable
OxMut: Safe mutable reference with shape.
OxPtrConst: Read-only shaped pointer for vtable use.
OxPtrMut: Mutable shaped pointer for vtable use.
OxPtrUninit: Uninitialized shaped pointer for vtable use.
OxRef: Safe read-only reference with shape.
PointerDef: Describes a pointer — including a vtable to query and alter its state, and the inner shape (the pointee type in the pointer).
PointerFlags: Flags to represent various characteristics of pointers
PointerVTable: Functions for interacting with a pointer
ProxyDef: Definition of a proxy type for custom serialization/deserialization.
PtrConst: A type-erased read-only pointer.
PtrMut: A type-erased mutable pointer (wide pointer) holding a data pointer and metadata.
PtrUninit: A type-erased pointer to uninitialized memory.
Repr: Describes base representation of the type
ResultDef: Describes a Result — including a vtable to query and alter its state, and the inner shapes (the T and E in Result<T, E>).
ResultVTable: Virtual table for Result<T, E>
ResultVTableBuilder: Builder for the vtable
SetDef: Fields for set types
SetVTable: Virtual table for a Set<T>
SetVTableBuilder: Builder for the vtable
Shape: Schema for reflection of a type — the core type in facet. Contains everything needed to inspect, allocate, and manipulate values at runtime.
ShapeBuilder: Builder for creating Shape instances.
ShapeFlags: Bit flags for common shape-level attributes.
ShapeRef: A lazy reference to a Shape via a function pointer.
SliceBuilderVTable: Functions for creating and manipulating slice builders.
SliceDef: Fields for slice types
SliceType: Describes a slice ([T])
SliceVTable: Virtual table for a slice-like type (like Vec<T>, but also HashSet<T>, etc.)
StructType: Common fields for struct-like types
StructTypeBuilder: Builder for StructType to enable shorter derive macro output
TaggedPtr: A pointer that uses the high bit (bit 63) as a tag to indicate wide vs thin.
TypeEnumBuilder: Builder that produces Type::User(UserType::Enum(...)).
TypeNameDisplay: A wrapper around &'static Shape that implements Display using the full type name (including generic parameters).
TypeNameOpts: Options for formatting the name of a type.
TypeOpsDirect: Type-specific operations for concrete types (uses thin pointers).
TypeOpsIndirect: Type-specific operations for generic containers (uses wide pointers with shape).
TypeParam: Represents a lifetime parameter, e.g., 'a or 'a: 'b + 'c.
TypeStructBuilder: Builder that produces Type::User(UserType::Struct(...)).
TypeUnionBuilder: Builder that produces Type::User(UserType::Union(...)).
TypedVTableDirectBuilder: Type-safe builder for VTableDirect.
UnionType: Common fields for union types
UnionTypeBuilder: Builder for constructing UnionType instances in const contexts.
UnsizedError: Tried to get the Layout of an unsized type
VTableDirect: VTable for concrete types with compile-time known traits.
VTableIndirect: VTable for generic containers with runtime trait resolution.
ValuePointerType: Describes the raw/reference pointer
Variant: Describes a variant of an enum
VariantBuilder: Builder for constructing Variant instances in const contexts.

Enums§

BaseRepr: Underlying byte layout representation
Characteristic: A characteristic a shape can have
Def: The semantic definition of a shape: is it more like a scalar, a map, a list?
DefaultSource: Source of a field’s default value.
DynDateTimeKind: The kind of datetime value (for dynamic value datetime support).
DynValueKind: The kind of value stored in a dynamic value.
EnumRepr: All possible representations for Rust enums — ie. the type/size of the discriminant
FieldError: Errors encountered when calling field_by_index or field_by_name
FunctionAbi: The calling ABI of a function pointer
KnownPointer: Represents common standard library pointer kinds
NumericType: Describes numeric types (integer/float)
Ox: Type-erased value with ownership tracking — like Cow but for any shape.
ParseError: Error returned by parse operations.
PointerType: Describes all pointer types
PrimitiveType: Describes built-in primitives (u32, bool, str, etc.)
PtrKind: The kind of a pointer based on its size.
ScalarType: All scalar types supported out of the box by facet.
SequenceType: Describes built-in sequence type (array, slice)
ShapeLayout: Layout of the shape
StructKind: Describes the kind of struct (useful for deserializing)
TextualType: Describes textual types (char/string)
TryBorrowInnerError: Error returned when try_borrow_inner fails.
TryFromError: Error returned when try_from fails to convert a value.
TryIntoInnerError: Error returned when try_into_inner fails.
Type: The definition of a shape in accordance to rust reference:
TypeOps: Type-erased TypeOps that can hold either Direct or Indirect style.
UserType: User-defined types (structs, enums, unions)
VTableErased: Type-erased VTable that can hold either Direct or Indirect style.
Variance: Variance of a type with respect to its type/lifetime parameters.

Constants§

MAX_VARIANCE_DEPTH: Maximum recursion depth for variance computation to prevent stack overflow on recursive types.

Traits§

Facet: Allows querying the Shape of a type, which in turn lets us inspect any fields, build a value of this type progressively, etc.
IterItem: A kind of item that an IterVTable returns
Write: A no_std compatible write trait used by facet serializers.

Functions§

of: Create a TypeId for a type.
ptr_kind: Determines the pointer kind for a given type.
shape_of: Returns the shape of a type as a function pointer.

Type Aliases§

ArrayAsMutPtrFn: Get mutable pointer to the data buffer of the array.
ArrayAsPtrFn: Get pointer to the data buffer of the array.
BorrowFn: Tries to obtain a reference to the inner value of the pointer.
DefaultInPlaceFn: Function type for default initialization in-place. Used by the #[facet(default)] attribute.
DowngradeIntoFn: Downgrades a strong pointer to a weak one.
DynArrayGetFn: Get an element from an array by index. Returns None if not an array or index out of bounds.
DynArrayLenFn: Get the length of an array. Returns None if not an array.
DynBeginArrayFn: Initialize the value as an empty array.
DynBeginObjectFn: Initialize the value as an empty object.
DynEndArrayFn: Finalize the array (optional, for shrinking capacity etc.).
DynEndObjectFn: Finalize the object (optional, for shrinking capacity etc.).
DynGetBoolFn: Get a boolean value. Returns None if not a bool.
DynGetBytesFn: Get a bytes reference. Returns None if not bytes.
DynGetDateTimeFn: Get datetime components from a datetime value.
DynGetF64Fn: Get a 64-bit float value. Returns None if not a number.
DynGetI64Fn: Get a signed 64-bit integer value. Returns None if not representable as i64.
DynGetKindFn: Get the kind of value stored.
DynGetStrFn: Get a string reference. Returns None if not a string.
DynGetU64Fn: Get an unsigned 64-bit integer value. Returns None if not representable as u64.
DynInsertObjectEntryFn: Insert a key-value pair into the object.
DynObjectGetEntryFn: Get a key-value pair from an object by index. Returns None if not an object or index out of bounds.
DynObjectGetFn: Get a value from an object by key. Returns None if not an object or key not found.
DynObjectGetMutFn: Get a mutable reference to a value from an object by key. Returns None if not an object or key not found.
DynObjectLenFn: Get the length of an object. Returns None if not an object.
DynPushArrayElementFn: Push an element to the array.
DynSetBoolFn: Set the value to a boolean.
DynSetBytesFn: Set the value to bytes.
DynSetDateTimeFn: Set the value to a datetime.
DynSetF64Fn: Set the value to a 64-bit float.
DynSetI64Fn: Set the value to a signed 64-bit integer.
DynSetNullFn: Set the value to null.
DynSetStrFn: Set the value to a string.
DynSetU64Fn: Set the value to an unsigned 64-bit integer.
FieldAttribute: An attribute that can be set on a field. This is now just an alias for ExtensionAttr - all attributes use the same representation.
InvariantsFn: Function type for type invariant validation. Used by the #[facet(invariants = fn)] attribute.
IterDeallocFn: Deallocate the iterator
IterInitWithValueFn: Create a new iterator that iterates over the provided value
IterNextBackFn: Advance the iterator in reverse, returning the next value from the end of the iterator.
IterNextFn: Advance the iterator, returning the next value from the iterator
IterSizeHintFn: Return the lower and upper bounds of the iterator, if known.
ListAsMutPtrFn: Get mutable pointer to the data buffer of the list.
ListAsMutPtrTypedFn: Get raw mutable pointer to the data buffer as *mut u8.
ListAsPtrFn: Get pointer to the data buffer of the list.
ListCapacityFn: Get the current capacity of the list.
ListGetFn: Get pointer to the element at index in the list, or None if the index is out of bounds.
ListGetMutFn: Get mutable pointer to the element at index in the list, or None if the index is out of bounds.
ListInitInPlaceWithCapacityFn: Initialize a list in place with a given capacity
ListLenFn: Get the number of items in the list
ListPushFn: Push an item to the list
ListReserveFn: Reserve capacity for at least additional more elements.
ListSetLenFn: Set the length of a list (for direct-fill operations).
LockFn: Acquires a lock on a mutex-like pointer
MapContainsKeyFn: Check if the map contains a key
MapFromPairSliceFn: Build a map from a contiguous slice of (K, V) pairs.
MapGetValuePtrFn: Get pointer to a value for a given key, returns None if not found
MapInitInPlaceWithCapacityFn: Initialize a map in place with a given capacity
MapInsertFn: Insert a key-value pair into the map
MapLenFn: Get the number of entries in the map
NdArrayAsMutPtrFn: Get mutable pointer to the data buffer of the array.
NdArrayAsPtrFn: Get pointer to the data buffer of the array.
NdArrayByteStrideFn: Get the i-th stride in the array in bytes, or None if the dimension index is out of bounds.
NdArrayCountFn: Get the total count of elements in the array.
NdArrayDimFn: Get the i-th dimension in the array, or None if the dimension index is out of bounds.
NdArrayGetFn: Get pointer to the element at index in the array, or None if the index is out of bounds.
NdArrayGetMutFn: Get mutable pointer to the element at index in the array, or None if the index is out of bounds.
NdArrayNDimFn: Get the number of dimensions in the array.
NewIntoFn: Creates a new pointer wrapping the given value.
OptionGetValueFn: Get the value contained in an option, if present
OptionInitNoneFn: Initialize an option with None
OptionInitSomeFn: Initialize an option with Some(value)
OptionIsSomeFn: Check if an option contains a value
OptionReplaceWithFn: Replace an existing option with a new value
ProxyConvertInFn: Function type for proxy deserialization: converts FROM proxy type INTO target type.
ProxyConvertOutFn: Function type for proxy serialization: converts FROM target type INTO proxy type.
ReadFn: Acquires a read lock on a reader-writer lock-like pointer
ResultGetErrFn: Get the Err value contained in a result, if present
ResultGetOkFn: Get the Ok value contained in a result, if present
ResultInitErrFn: Initialize a result with Err(value)
ResultInitOkFn: Initialize a result with Ok(value)
ResultIsOkFn: Check if a result is Ok
SetContainsFn: Check if the set contains a value
SetInitInPlaceWithCapacityFn: Initialize a set in place with a given capacity
SetInsertFn: Insert a value in the set if not already contained, returning true if the value wasn’t present before
SetLenFn: Get the number of values in the set
ShapeAttribute: An attribute that can be applied to a shape. This is now just an alias for ExtensionAttr - all attributes use the same representation.
SkipSerializingIfFn: A function that, if present, determines whether field should be included in the serialization step. Takes a type-erased pointer and returns true if the field should be skipped.
SliceAsMutPtrFn: Get mutable pointer to the data buffer of the slice
SliceAsPtrFn: Get pointer to the data buffer of the slice
SliceBuilderConvertFn: Converts a slice builder into a pointer. This takes ownership of the builder and frees the backing storage.
SliceBuilderFreeFn: Frees a slice builder without converting it into a pointer
SliceBuilderNewFn: Creates a new slice builder for a pointer: ie. for Arc<[u8]>, it builds a Vec<u8> internally, to which you can push, and then turn into an Arc<[u8]> at the last stage.
SliceBuilderPushFn: Pushes a value into a slice builder.
SliceLenFn: Get the number of items in the slice
TruthyFn: Function type for truthiness checks used by skip_unless_truthy-style helpers.
TypeNameFn: Function pointer type for formatting type names.
UpgradeIntoFn: Tries to upgrade the weak pointer to a strong one.
VariantAttribute: An attribute that can be set on an enum variant. This is now just an alias for ExtensionAttr - all attributes use the same representation.
WriteFn: Acquires a write lock on a reader-writer lock-like pointer

Crate facet_core

Crate facet_core Copy item path

§facet-core

§Sponsors

§Special thanks

§License

Modules§

Macros§

Structs§

Enums§

Constants§

Traits§

Functions§

Type Aliases§

Crate facet_core