Rollup merge of #104976 - WaffleLapkin:move_comments, r=cjgillot

Prefer doc comments over `//`-comments in compiler

Doc comments are generally nicer: they show up in the documentation, they are shown in IDEs when you hover other mentions of items, etc. Thus it makes sense to use them instead of `//`-comments.

compiler/rustc_infer/src/infer/free_regions.rs

@@ -29,10 +29,10 @@ impl<'a, 'tcx> RegionRelations<'a, 'tcx> {
 
 #[derive(Clone, Debug)]
 pub struct FreeRegionMap<'tcx> {
-    // Stores the relation `a < b`, where `a` and `b` are regions.
-    //
-    // Invariant: only free regions like `'x` or `'static` are stored
-    // in this relation, not scopes.
+    /// Stores the relation `a < b`, where `a` and `b` are regions.
+    ///
+    /// Invariant: only free regions like `'x` or `'static` are stored
+    /// in this relation, not scopes.
     pub(crate) relation: TransitiveRelation<Region<'tcx>>,
 }
 

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -410,19 +410,19 @@ impl<'tcx> InferCtxt<'tcx> {
     }
 }
 
-// Visitor that requires that (almost) all regions in the type visited outlive
-// `least_region`. We cannot use `push_outlives_components` because regions in
-// closure signatures are not included in their outlives components. We need to
-// ensure all regions outlive the given bound so that we don't end up with,
-// say, `ReVar` appearing in a return type and causing ICEs when other
-// functions end up with region constraints involving regions from other
-// functions.
-//
-// We also cannot use `for_each_free_region` because for closures it includes
-// the regions parameters from the enclosing item.
-//
-// We ignore any type parameters because impl trait values are assumed to
-// capture all the in-scope type parameters.
+/// Visitor that requires that (almost) all regions in the type visited outlive
+/// `least_region`. We cannot use `push_outlives_components` because regions in
+/// closure signatures are not included in their outlives components. We need to
+/// ensure all regions outlive the given bound so that we don't end up with,
+/// say, `ReVar` appearing in a return type and causing ICEs when other
+/// functions end up with region constraints involving regions from other
+/// functions.
+///
+/// We also cannot use `for_each_free_region` because for closures it includes
+/// the regions parameters from the enclosing item.
+///
+/// We ignore any type parameters because impl trait values are assumed to
+/// capture all the in-scope type parameters.
 pub struct ConstrainOpaqueTypeRegionVisitor<'tcx, OP: FnMut(ty::Region<'tcx>)> {
     pub tcx: TyCtxt<'tcx>,
     pub op: OP,

compiler/rustc_infer/src/infer/opaque_types/table.rs

@@ -9,10 +9,10 @@ use super::{OpaqueTypeDecl, OpaqueTypeMap};
 
 #[derive(Default, Debug, Clone)]
 pub struct OpaqueTypeStorage<'tcx> {
-    // Opaque types found in explicit return types and their
-    // associated fresh inference variable. Writeback resolves these
-    // variables to get the concrete type, which can be used to
-    // 'de-opaque' OpaqueTypeDecl, after typeck is done with all functions.
+    /// Opaque types found in explicit return types and their
+    /// associated fresh inference variable. Writeback resolves these
+    /// variables to get the concrete type, which can be used to
+    /// 'de-opaque' OpaqueTypeDecl, after typeck is done with all functions.
     pub opaque_types: OpaqueTypeMap<'tcx>,
 }