Enum RDefKind 

pub enum RDefKind {
    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(MacroKinds),
    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(MacroKinds)

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.

Trait Implementations

impl<S> SInto<S, DefKind> for DefKind

fn sinto(&self, tcx: &S) -> DefKind