rustc_middle/query/
into_query_key.rs

1use rustc_hir::OwnerId;
2use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId, ModDefId};
3
4/// Argument-conversion trait used by some queries and other `TyCtxt` methods.
5///
6/// A function that accepts an `impl IntoQueryKey<DefId>` argument can be thought
7/// of as taking a [`DefId`], except that callers can also pass a [`LocalDefId`]
8/// or values of other narrower ID types, as long as they have a trivial conversion
9/// to `DefId`.
10///
11/// Using a dedicated trait instead of [`Into`] makes the purpose of the conversion
12/// more explicit, and makes occurrences easier to search for.
13pub trait IntoQueryKey<K> {
14    /// Argument conversion from `Self` to `K`.
15    /// This should always be a very cheap conversion, e.g. [`LocalDefId::to_def_id`].
16    fn into_query_key(self) -> K;
17}
18
19/// Any type can be converted to itself.
20///
21/// This is useful in generic or macro-generated code where we don't know whether
22/// conversion is actually needed, so that we can do a conversion unconditionally.
23impl<K> IntoQueryKey<K> for K {
24    #[inline(always)]
25    fn into_query_key(self) -> K {
26        self
27    }
28}
29
30impl IntoQueryKey<LocalDefId> for OwnerId {
31    #[inline(always)]
32    fn into_query_key(self) -> LocalDefId {
33        self.def_id
34    }
35}
36
37impl IntoQueryKey<DefId> for LocalDefId {
38    #[inline(always)]
39    fn into_query_key(self) -> DefId {
40        self.to_def_id()
41    }
42}
43
44impl IntoQueryKey<DefId> for OwnerId {
45    #[inline(always)]
46    fn into_query_key(self) -> DefId {
47        self.to_def_id()
48    }
49}
50
51impl IntoQueryKey<DefId> for ModDefId {
52    #[inline(always)]
53    fn into_query_key(self) -> DefId {
54        self.to_def_id()
55    }
56}
57
58impl IntoQueryKey<DefId> for LocalModDefId {
59    #[inline(always)]
60    fn into_query_key(self) -> DefId {
61        self.to_def_id()
62    }
63}
64
65impl IntoQueryKey<LocalDefId> for LocalModDefId {
66    #[inline(always)]
67    fn into_query_key(self) -> LocalDefId {
68        self.into()
69    }
70}
rustc_middle/query/into_query_key.rs

rustc_middle/query/
into_query_key.rs
