[clang-tools-extra] [clang-tidy]bugprone-unused-return-value ignore `++` and `--` operator overloading (PR #84922)

[Piotr Zegar via cfe-commits]

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@@ -31,9 +31,20 @@ AST_MATCHER_P(FunctionDecl, isInstantiatedFrom, Matcher<FunctionDecl>,
                               Finder, Builder);
 }
 
-AST_MATCHER_P(CXXMethodDecl, isOperatorOverloading,
-              llvm::SmallVector<OverloadedOperatorKind>, Kinds) {
-  return llvm::is_contained(Kinds, Node.getOverloadedOperator());
+constexpr std::initializer_list<OverloadedOperatorKind>
+    AssignmentOverloadedOperatorKinds = {
+        OO_Equal,      OO_PlusEqual,     OO_MinusEqual,          OO_StarEqual,
+        OO_SlashEqual, OO_PercentEqual,  OO_CaretEqual,          OO_AmpEqual,
+        OO_PipeEqual,  OO_LessLessEqual, OO_GreaterGreaterEqual, OO_PlusPlus,
+        OO_MinusMinus};
+
+AST_MATCHER(CXXOperatorCallExpr, isAssignmentOverloadedOperatorCall) {
+  return llvm::is_contained(AssignmentOverloadedOperatorKinds,
+                            Node.getOperator());
+}
+AST_MATCHER(CXXMethodDecl, isAssignmentOverloadedOperatorMethod) {
+  return llvm::is_contained(AssignmentOverloadedOperatorKinds,
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PiotrZSL wrote:

getOverloadedOperator belongs to FunctionDecl, change this from Method to Function, and same in calee, in such case you will also cover calls to free standing operators called directly.

https://github.com/llvm/llvm-project/pull/84922