Index: clang/lib/Format/TokenAnnotator.h
===================================================================
--- clang/lib/Format/TokenAnnotator.h
+++ clang/lib/Format/TokenAnnotator.h
@@ -170,17 +170,27 @@
 /// \c UnwrappedLine.
 class TokenAnnotator {
 public:
-  TokenAnnotator(const FormatStyle &Style, const AdditionalKeywords &Keywords)
-      : Style(Style), Keywords(Keywords) {}
+  TokenAnnotator(const FormatStyle &Style, const AdditionalKeywords &Keywords);
 
   /// Adapts the indent levels of comment lines to the indent of the
   /// subsequent line.
   // FIXME: Can/should this be done in the UnwrappedLineParser?
   void setCommentLineLevels(SmallVectorImpl<AnnotatedLine *> &Lines) const;
 
-  void annotate(AnnotatedLine &Line) const;
+  void annotate(AnnotatedLine &Line);
   void calculateFormattingInformation(AnnotatedLine &Line) const;
 
+  enum class ScopeType : std::int8_t {
+    // Not contained within scope block.
+    None,
+    // Contained in class declaration/definition.
+    Class,
+    // Contained within function definition.
+    Function,
+    // Contained within other scope block (loop, if/else, etc).
+    Other,
+  };
+
 private:
   /// Calculate the penalty for splitting before \c Tok.
   unsigned splitPenalty(const AnnotatedLine &Line, const FormatToken &Tok,
@@ -220,6 +230,8 @@
   const FormatStyle &Style;
 
   const AdditionalKeywords &Keywords;
+
+  SmallVector<ScopeType> Scopes;
 };
 
 } // end namespace format
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -111,9 +111,10 @@
 class AnnotatingParser {
 public:
   AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
-                   const AdditionalKeywords &Keywords)
-      : Style(Style), Line(Line), CurrentToken(Line.First), AutoFound(false),
-        Keywords(Keywords) {
+                   const AdditionalKeywords &Keywords,
+                   SmallVector<TokenAnnotator::ScopeType> &TrackedScopes)
+      : Scopes(TrackedScopes), Style(Style), Line(Line),
+        CurrentToken(Line.First), AutoFound(false), Keywords(Keywords) {
     Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
     resetTokenMetadata();
   }
@@ -847,6 +848,9 @@
     unsigned CommaCount = 0;
     while (CurrentToken) {
       if (CurrentToken->is(tok::r_brace)) {
+        // Handle unbalanced braces
+        if (Scopes.size() > 1)
+          Scopes.pop_back();
         assert(OpeningBrace.Optional == CurrentToken->Optional);
         OpeningBrace.MatchingParen = CurrentToken;
         CurrentToken->MatchingParen = &OpeningBrace;
@@ -1146,6 +1150,27 @@
         if (Previous && Previous->getType() != TT_DictLiteral)
           Previous->setType(TT_SelectorName);
       }
+      switch (Tok->getType()) {
+      case TT_FunctionLBrace:
+      case TT_LambdaLBrace:
+        Scopes.push_back(TokenAnnotator::ScopeType::Function);
+        break;
+      case TT_ClassLBrace:
+      case TT_StructLBrace:
+      case TT_UnionLBrace:
+        Scopes.push_back(TokenAnnotator::ScopeType::Class);
+        break;
+      case TT_EnumLBrace:
+      case TT_ControlStatementLBrace:
+      case TT_ElseLBrace:
+      case TT_BracedListLBrace:
+      case TT_CompoundRequirementLBrace:
+      case TT_ObjCBlockLBrace:
+      case TT_RecordLBrace:
+      case TT_RequiresExpressionLBrace:
+      default:
+        Scopes.push_back(TokenAnnotator::ScopeType::Other);
+      }
       if (!parseBrace())
         return false;
       break;
@@ -1176,6 +1201,9 @@
     case tok::r_square:
       return false;
     case tok::r_brace:
+      // Handle unbalanced braces
+      if (Scopes.size() > 1)
+        Scopes.pop_back();
       // Lines can start with '}'.
       if (Tok->Previous)
         return false;
@@ -2446,6 +2474,25 @@
     if (IsExpression && !Contexts.back().CaretFound)
       return TT_BinaryOperator;
 
+    // Opeartors at class scope are likely pointer or reference members.
+    if (Scopes.back() == TokenAnnotator::ScopeType::Class)
+      return TT_PointerOrReference;
+
+    // It's more likely that & represents operator& than an uninitialized
+    // reference.
+    if (Tok.is(tok::amp) && (PrevToken && PrevToken->Tok.isAnyIdentifier()) &&
+        (!PrevToken->getPreviousNonComment() ||
+         PrevToken->getPreviousNonComment()->isOneOf(tok::amp, tok::period,
+                                                     tok::arrow, tok::arrowstar,
+                                                     tok::periodstar)) &&
+        (NextToken && NextToken->Tok.isAnyIdentifier()) &&
+        (NextToken->getNextNonComment() &&
+         (NextToken->getNextNonComment()->isOneOf(
+             tok::amp, tok::semi, tok::period, tok::arrow, tok::arrowstar,
+             tok::periodstar)))) {
+      return TT_BinaryOperator;
+    }
+
     return TT_PointerOrReference;
   }
 
@@ -2476,6 +2523,7 @@
   }
 
   SmallVector<Context, 8> Contexts;
+  SmallVector<TokenAnnotator::ScopeType> &Scopes;
 
   const FormatStyle &Style;
   AnnotatedLine &Line;
@@ -2724,6 +2772,12 @@
 
 } // end anonymous namespace
 
+TokenAnnotator::TokenAnnotator(const FormatStyle &Style,
+                               const AdditionalKeywords &Keywords)
+    : Style(Style), Keywords(Keywords) {
+  Scopes.push_back(ScopeType::None);
+}
+
 void TokenAnnotator::setCommentLineLevels(
     SmallVectorImpl<AnnotatedLine *> &Lines) const {
   const AnnotatedLine *NextNonCommentLine = nullptr;
@@ -2763,11 +2817,11 @@
   return Result;
 }
 
-void TokenAnnotator::annotate(AnnotatedLine &Line) const {
+void TokenAnnotator::annotate(AnnotatedLine &Line) {
   for (auto &Child : Line.Children)
     annotate(*Child);
 
-  AnnotatingParser Parser(Style, Line, Keywords);
+  AnnotatingParser Parser(Style, Line, Keywords, Scopes);
   Line.Type = Parser.parseLine();
 
   // With very deep nesting, ExpressionParser uses lots of stack and the
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -11267,6 +11267,13 @@
 
   verifyFormat("int operator()(T (&&)[N]) { return 1; }");
   verifyFormat("int operator()(T (&)[N]) { return 0; }");
+
+  verifyFormat("val1 & val2;");
+  verifyFormat("val1 & val2 & val3;");
+  verifyFormat("class c {\n"
+               "  void func(type &a) { a & member; }\n"
+               "  anotherType &member;\n"
+               "}");
 }
 
 TEST_F(FormatTest, UnderstandsAttributes) {
Index: clang/unittests/Format/TokenAnnotatorTest.cpp
===================================================================
--- clang/unittests/Format/TokenAnnotatorTest.cpp
+++ clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -175,6 +175,57 @@
   ASSERT_EQ(Tokens.size(), 17u) << Tokens;
   EXPECT_TOKEN(Tokens[9], tok::ampamp, TT_PointerOrReference);
   EXPECT_TOKEN(Tokens[12], tok::ampamp, TT_PointerOrReference);
+
+  Tokens = annotate("Type1 &val1 = val2;");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_PointerOrReference);
+
+  Tokens = annotate("Type1 *val1 = &val2;");
+  ASSERT_EQ(Tokens.size(), 8u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::star, TT_PointerOrReference);
+  EXPECT_TOKEN(Tokens[4], tok::amp, TT_UnaryOperator);
+
+  Tokens = annotate("val1 & val2;");
+  ASSERT_EQ(Tokens.size(), 5u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("val1 & val2.member;");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("val1 & val2 & val3;");
+  ASSERT_EQ(Tokens.size(), 7u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[3], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("val1 & val2 // comment\n"
+                    "     & val3;");
+  ASSERT_EQ(Tokens.size(), 8u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[4], tok::amp, TT_BinaryOperator);
+
+  Tokens =
+      annotate("val1 & val2.member & val3.member() & val4 & val5->member;");
+  ASSERT_EQ(Tokens.size(), 19u) << Tokens;
+  EXPECT_TOKEN(Tokens[1], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[5], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[11], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[13], tok::amp, TT_BinaryOperator);
+
+  Tokens = annotate("class c {\n"
+                    "  void func(type &a) { a & member; }\n"
+                    "  anotherType &member;\n"
+                    "}");
+  ASSERT_EQ(Tokens.size(), 22u) << Tokens;
+  EXPECT_TOKEN(Tokens[7], tok::amp, TT_PointerOrReference);
+  EXPECT_TOKEN(Tokens[12], tok::amp, TT_BinaryOperator);
+  EXPECT_TOKEN(Tokens[17], tok::amp, TT_PointerOrReference);
+
+  Tokens = annotate("struct S {\n"
+                    "  auto Mem = C & D;\n"
+                    "}");
+  ASSERT_EQ(Tokens.size(), 12u) << Tokens;
+  EXPECT_TOKEN(Tokens[7], tok::amp, TT_BinaryOperator);
 }
 
 TEST_F(TokenAnnotatorTest, UnderstandsUsesOfPlusAndMinus) {