apply various formatting nits

src/librustc/infer/lexical_region_resolve/mod.rs

@@ -83,7 +83,7 @@ pub enum RegionResolutionError<'tcx> {
     ),
 
     /// Indicates a `'b: 'a` constraint where `'a` is in a universe that
-    /// cannot name the placeholder `'b`
+    /// cannot name the placeholder `'b`.
     UpperBoundUniverseConflict(
         RegionVid,
         RegionVariableOrigin,
@@ -449,7 +449,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
             return true;
         }
 
-        // If both a and b are free, consult the declared
+        // If both `a` and `b` are free, consult the declared
         // relationships.  Note that this can be more precise than the
         // `lub` relationship defined below, since sometimes the "lub"
         // is actually the `postdom_upper_bound` (see
@@ -460,7 +460,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
         }
 
         // For other cases, leverage the LUB code to find the LUB and
-        // check if it is equal to b.
+        // check if it is equal to `b`.
         self.lub_concrete_regions(a, b) == b
     }
 
@@ -491,7 +491,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
             }
 
             (&ReStatic, _) | (_, &ReStatic) => {
-                // nothing lives longer than static
+                // nothing lives longer than `'static`
                 self.tcx().lifetimes.re_static
             }
 
@@ -501,14 +501,14 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
             | (r @ ReFree(_), &ReEmpty(_))
             | (&ReEmpty(_), r @ ReScope(_))
             | (r @ ReScope(_), &ReEmpty(_)) => {
-                // all empty regions are less than early-bound, free,
-                // and scope regions
+                // All empty regions are less than early-bound, free,
+                // and scope regions.
                 r
             }
 
             (&ReEmpty(a_ui), &ReEmpty(b_ui)) => {
-                // empty regions are ordered according to the universe
-                // they are associated with
+                // Empty regions are ordered according to the universe
+                // they are associated with.
                 let ui = a_ui.min(b_ui);
                 self.tcx().mk_region(ReEmpty(ui))
             }

src/librustc/infer/outlives/verify.rs

@@ -68,7 +68,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
             // being tested is `'empty`.
             VerifyBound::IsEmpty
         } else {
-            // If we can find any other bound R such that `T: R`, then
+            // If we can find any other bound `R` such that `T: R`, then
             // we don't need to check for `'empty`, because `R: 'empty`.
             VerifyBound::AnyBound(any_bounds)
         }

src/librustc/ty/context.rs

@@ -173,10 +173,10 @@ pub struct CommonTypes<'tcx> {
 }
 
 pub struct CommonLifetimes<'tcx> {
-    /// ReEmpty in the root universe
+    /// `ReEmpty` in the root universe.
     pub re_root_empty: Region<'tcx>,
 
-    /// ReStatic
+    /// `ReStatic`
     pub re_static: Region<'tcx>,
 
     /// Erased region, used after type-checking

src/librustc/ty/free_region_map.rs

@@ -56,7 +56,7 @@ impl<'tcx> FreeRegionMap<'tcx> {
         }
     }
 
-    /// Check whether `r_a <= r_b` is found in the relation
+    /// Check whether `r_a <= r_b` is found in the relation.
     fn check_relation(&self, r_a: Region<'tcx>, r_b: Region<'tcx>) -> bool {
         r_a == r_b || self.relation.contains(&r_a, &r_b)
     }

src/librustc/ty/sty.rs

@@ -1415,9 +1415,9 @@ pub enum RegionKind {
     /// Empty lifetime is for data that is never accessed.  We tag the
     /// empty lifetime with a universe -- the idea is that we don't
     /// want `exists<'a> { forall<'b> { 'b: 'a } }` to be satisfiable.
-    /// Therefore, the `'empty` in a universe U is less than all
-    /// regions visible from U, but not less than regions not visible
-    /// from U.
+    /// Therefore, the `'empty` in a universe `U` is less than all
+    /// regions visible from `U`, but not less than regions not visible
+    /// from `U`.
     ReEmpty(ty::UniverseIndex),
 
     /// Erased region, used by trait selection, in MIR and during codegen.