Type Alias rustc_resolve::Res
source · pub(crate) type Res = Res<NodeId>;
Aliased Type§
enum Res {
Def(DefKind, DefId),
PrimTy(PrimTy),
SelfTyParam {
trait_: DefId,
},
SelfTyAlias {
alias_to: DefId,
forbid_generic: bool,
is_trait_impl: bool,
},
SelfCtor(DefId),
Local(NodeId),
ToolMod,
NonMacroAttr(NonMacroAttrKind),
Err,
}
Variants§
Def(DefKind, DefId)
Definition having a unique ID (DefId
), corresponds to something defined in user code.
Not bound to a specific namespace.
PrimTy(PrimTy)
A primitive type such as i32
or str
.
Belongs to the type namespace.
SelfTyParam
The Self
type, as used within a trait.
Belongs to the type namespace.
See the examples on [Res::SelfTyAlias
] for details.
SelfTyAlias
Fields
alias_to: DefId
The item introducing the Self
type alias. Can be used in the type_of
query
to get the underlying type.
forbid_generic: bool
Whether the Self
type is disallowed from mentioning generics (i.e. when used in an
anonymous constant).
HACK(min_const_generics): self types also have an optional requirement to not
mention any generic parameters to allow the following with min_const_generics
:
impl Foo { fn test() -> [u8; std::mem::size_of::<Self>()] { todo!() } }
struct Bar([u8; baz::<Self>()]);
const fn baz<T>() -> usize { 10 }
We do however allow Self
in repeat expression even if it is generic to not break code
which already works on stable while causing the const_evaluatable_unchecked
future
compat lint:
fn foo<T>() {
let _bar = [1_u8; std::mem::size_of::<*mut T>()];
}
The Self
type, as used somewhere other than within a trait.
Belongs to the type namespace.
Examples:
struct Bar(Box<Self>); // SelfTyAlias
trait Foo {
fn foo() -> Box<Self>; // SelfTyParam
}
impl Bar {
fn blah() {
let _: Self; // SelfTyAlias
}
}
impl Foo for Bar {
fn foo() -> Box<Self> { // SelfTyAlias
let _: Self; // SelfTyAlias
todo!()
}
}
See also [Res::SelfCtor
].
SelfCtor(DefId)
The Self
constructor, along with the [DefId
]
of the impl it is associated with.
Belongs to the value namespace.
See also [Res::SelfTyParam
] and [Res::SelfTyAlias
].
Local(NodeId)
A local variable or function parameter.
Belongs to the value namespace.
ToolMod
A tool attribute module; e.g., the rustfmt
in #[rustfmt::skip]
.
Belongs to the type namespace.
NonMacroAttr(NonMacroAttrKind)
An attribute that is not implemented via macro.
E.g., #[inline]
and #[rustfmt::skip]
, which are essentially directives,
as opposed to #[test]
, which is a builtin macro.
Belongs to the macro namespace.
Err
Name resolution failed. We use a dummy Res
variant so later phases
of the compiler won’t crash and can instead report more errors.
Not bound to a specific namespace.
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: 12 bytes
Size for each variant:
Def
: 11 bytesPrimTy
: 2 bytesSelfTyParam
: 11 bytesSelfTyAlias
: 11 bytesSelfCtor
: 11 bytesLocal
: 7 bytesToolMod
: 0 bytesNonMacroAttr
: 7 bytesErr
: 0 bytes