Index: clang-tools-extra/clangd/InlayHints.cpp
===================================================================
--- clang-tools-extra/clangd/InlayHints.cpp
+++ clang-tools-extra/clangd/InlayHints.cpp
@@ -10,6 +10,7 @@
 #include "Config.h"
 #include "HeuristicResolver.h"
 #include "ParsedAST.h"
+#include "clang/AST/Decl.h"
 #include "clang/AST/DeclarationName.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/RecursiveASTVisitor.h"
@@ -392,6 +393,7 @@
     // Don't show hints for variadic parameters.
     size_t FixedParamCount = getFixedParamCount(Callee);
     size_t ArgCount = std::min(FixedParamCount, Args.size());
+    auto Params = Callee->parameters();
 
     NameVec ParameterNames = chooseParameterNames(Callee, ArgCount);
 
@@ -402,12 +404,18 @@
 
     for (size_t I = 0; I < ArgCount; ++I) {
       StringRef Name = ParameterNames[I];
-      if (!shouldHint(Args[I], Name))
-        continue;
+      bool NameHint = shouldNameHint(Args[I], Name);
+      std::string Suffix = ": ";
+      if (!NameHint) {
+        Name = "";
+        Suffix = "";
+      }
+      Suffix += getRefSuffix(Params[I]);
 
-      addInlayHint(Args[I]->getSourceRange(), HintSide::Left,
-                   InlayHintKind::ParameterHint, /*Prefix=*/"", Name,
-                   /*Suffix=*/": ");
+      if (!Name.empty() || !Suffix.empty()) {
+        addInlayHint(Args[I]->getSourceRange(), HintSide::Left,
+                     InlayHintKind::ParameterHint, /*Prefix=*/"", Name, Suffix);
+      }
     }
   }
 
@@ -434,12 +442,21 @@
     return WhatItIsSetting.equals_insensitive(ParamNames[0]);
   }
 
-  bool shouldHint(const Expr *Arg, StringRef ParamName) {
+  StringRef getRefSuffix(const ParmVarDecl *Param) {
+    // If the parameter is a non-const reference type, print an inlay hint
+    auto Type = Param->getType();
+    return Type->isReferenceType() &&
+                   !Type.getNonReferenceType().isConstQualified()
+               ? (Type->isLValueReferenceType() ? "&" : "&&")
+               : "";
+  }
+
+  bool shouldNameHint(const Expr *Arg, StringRef ParamName) {
     if (ParamName.empty())
       return false;
 
     // If the argument expression is a single name and it matches the
-    // parameter name exactly, omit the hint.
+    // parameter name exactly, omit the name hint.
     if (ParamName == getSpelledIdentifier(Arg))
       return false;