More comments for lower_inline_const

compiler/rustc_mir_build/src/thir/pattern/mod.rs

@@ -688,7 +688,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         pattern
     }
 
-    /// Converts inline const patterns.
+    /// Lowers an inline const block (e.g. `const { 1 + 1 }`) to a pattern.
     fn lower_inline_const(
         &mut self,
         block: &'tcx hir::ConstBlock,
@@ -708,6 +708,9 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
 
         let ct = ty::UnevaluatedConst { def: def_id.to_def_id(), args };
         let subpattern = self.const_to_pat(ty::Const::new_unevaluated(self.tcx, ct), ty, id, span);
+
+        // Wrap the pattern in a marker node to indicate that it is the result
+        // of lowering an inline const block.
         PatKind::ExpandedConstant { subpattern, def_id: def_id.to_def_id(), is_inline: true }
     }