Enum DefKind

pub enum DefKind {
    Mod,
    Struct,
    Union,
    Enum,
    Variant,
    Trait,
    TyAlias,
    ForeignTy,
    TraitAlias,
    AssocTy,
    TyParam,
    Fn,
    Const,
    ConstParam,
    Static {
        safety: Safety,
        mutability: Mutability,
        nested: bool,
    },
    Ctor(CtorOf, CtorKind),
    AssocFn,
    AssocConst,
    Macro(MacroKind),
    ExternCrate,
    Use,
    ForeignMod,
    AnonConst,
    InlineConst,
    OpaqueTy,
    Field,
    LifetimeParam,
    GlobalAsm,
    Impl {
        of_trait: bool,
    },
    Closure,
    SyntheticCoroutineBody,
}

What kind of definition something is; e.g., mod vs struct. enum DefPathData may need to be updated if a new variant is added here.

Variants

Mod

Struct

Refers to the struct itself, DefKind::Ctor refers to its constructor if it exists.

Union

Enum

Variant

Refers to the variant itself, DefKind::Ctor refers to its constructor if it exists.

Trait

TyAlias

Type alias: type Foo = Bar;

ForeignTy

Type from an extern block.

TraitAlias

Trait alias: trait IntIterator = Iterator<Item = i32>;

AssocTy

Associated type: trait MyTrait { type Assoc; }

TyParam

Type parameter: the T in struct Vec<T> { ... }

Fn

Const

ConstParam

Constant generic parameter: struct Foo<const N: usize> { ... }

Static

Fields

safety: Safety

Whether it’s a unsafe static, safe static (inside extern only) or just a static.

mutability: Mutability

Whether it’s a static mut or just a static.

nested: bool

Whether it’s an anonymous static generated for nested allocations.

Ctor(CtorOf, CtorKind)

Refers to the struct or enum variant’s constructor.

The reason Ctor exists in addition to DefKind::Struct and DefKind::Variant is because structs and enum variants exist in the type namespace, whereas struct and enum variant constructors exist in the value namespace.

You may wonder why enum variants exist in the type namespace as opposed to the value namespace. Check out RFC 2593 for intuition on why that is.

AssocFn

Associated function: impl MyStruct { fn associated() {} } or trait Foo { fn associated() {} }

AssocConst

Associated constant: trait MyTrait { const ASSOC: usize; }

Macro(MacroKind)

ExternCrate

Use

ForeignMod

An extern block.

AnonConst

Anonymous constant, e.g. the 1 + 2 in [u8; 1 + 2].

Not all anon-consts are actually still relevant in the HIR. We lower trivial const-arguments directly to hir::ConstArgKind::Path, at which point the definition for the anon-const ends up unused and incomplete.

We do not provide any a Span for the definition and pretty much all other queries also ICE when using this DefId. Given that the DefId of such constants should only be reachable by iterating all definitions of a given crate, you should not have to worry about this.

InlineConst

An inline constant, e.g. const { 1 + 2 }

OpaqueTy

Opaque type, aka impl Trait.

Field

A field in a struct, enum or union. e.g.

• bar in struct Foo { bar: u8 }
• Foo::Bar::0 in enum Foo { Bar(u8) }

LifetimeParam

Lifetime parameter: the 'a in struct Foo<'a> { ... }

GlobalAsm

A use of global_asm!.

Impl

Fields

of_trait: bool

Closure

A closure, coroutine, or coroutine-closure.

These are all represented with the same ExprKind::Closure in the AST and HIR, which makes it difficult to distinguish these during def collection. Therefore, we treat them all the same, and code which needs to distinguish them can match or hir::ClosureKind or type_of.

SyntheticCoroutineBody

The definition of a synthetic coroutine body created by the lowering of a coroutine-closure, such as an async closure.

Implementations

impl DefKind

pub fn descr(self, def_id: DefId) -> &'static str

Get an English description for the item’s kind.

If you have access to TyCtxt, use TyCtxt::def_descr or TyCtxt::def_kind_descr instead, because they give better information for coroutines and associated functions.

pub fn article(&self) -> &'static str

Gets an English article for the definition.

If you have access to TyCtxt, use TyCtxt::def_descr_article or TyCtxt::def_kind_descr_article instead, because they give better information for coroutines and associated functions.

pub fn ns(&self) -> Option<Namespace>

pub fn def_path_data(self, name: Symbol) -> DefPathData

pub fn is_fn_like(self) -> bool

pub fn has_codegen_attrs(self) -> bool

Whether query get_codegen_attrs should be used with this definition.

Trait Implementations

impl Clone for DefKind

fn clone(&self) -> DefKind

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DefKind

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

Formats the value using the given formatter.

impl<__D: SpanDecoder> Decodable<__D> for DefKind

fn decode(__decoder: &mut __D) -> Self

impl<__E: SpanEncoder> Encodable<__E> for DefKind

fn encode(&self, __encoder: &mut __E)

impl Hash for DefKind

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<__CTX> HashStable<__CTX> for DefKind

where __CTX: HashStableContext,

fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

impl PartialEq for DefKind

fn eq(&self, other: &DefKind) -> 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 DefKind

impl Eq for DefKind

impl StructuralPartialEq for DefKind

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 3 bytes

Size for each variant:

• Mod: 0 bytes
• Struct: 0 bytes
• Union: 0 bytes
• Enum: 0 bytes
• Variant: 0 bytes
• Trait: 0 bytes
• TyAlias: 0 bytes
• ForeignTy: 0 bytes
• TraitAlias: 0 bytes
• AssocTy: 0 bytes
• TyParam: 0 bytes
• Fn: 0 bytes
• Const: 0 bytes
• ConstParam: 0 bytes
• Static: 3 bytes
• Ctor: 3 bytes
• AssocFn: 0 bytes
• AssocConst: 0 bytes
• Macro: 2 bytes
• ExternCrate: 0 bytes
• Use: 0 bytes
• ForeignMod: 0 bytes
• AnonConst: 0 bytes
• InlineConst: 0 bytes
• OpaqueTy: 0 bytes
• Field: 0 bytes
• LifetimeParam: 0 bytes
• GlobalAsm: 0 bytes
• Impl: 2 bytes
• Closure: 0 bytes
• SyntheticCoroutineBody: 0 bytes