"Operator has not been user-defined." is displayed only is operator can be user-defined

libsolidity/ast/OverridableOperators.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <liblangutil/Token.h>
+
+#include <vector>
+
+namespace solidity::frontend
+{
+
+std::vector<langutil::Token> const overridableOperators = {
+	langutil::Token::BitOr,
+	langutil::Token::BitAnd,
+	langutil::Token::BitXor,
+	langutil::Token::Add,
+	langutil::Token::Sub,
+	langutil::Token::Mul,
+	langutil::Token::Div,
+	langutil::Token::Mod,
+	langutil::Token::Equal,
+	langutil::Token::NotEqual,
+	langutil::Token::LessThan,
+	langutil::Token::GreaterThan,
+	langutil::Token::LessThanOrEqual,
+	langutil::Token::GreaterThanOrEqual,
+	langutil::Token::BitNot,
+	langutil::Token::SHL,
+	langutil::Token::SAR,
+	langutil::Token::Exp,
+	langutil::Token::Not
+};
+
+}

libsolidity/ast/Types.cpp

@@ -25,6 +25,7 @@
 
 #include <libsolidity/ast/AST.h>
 #include <libsolidity/ast/TypeProvider.h>
+#include <libsolidity/ast/OverridableOperators.h>
 
 #include <libsolidity/analysis/ConstantEvaluator.h>
 
@@ -387,7 +388,7 @@ vector<UsingForDirective const*> usingForDirectivesForType(Type const& _type, AS
 
 Result<FunctionDefinition const*> Type::userDefinedOperator(Token _token, ASTNode const& _scope, bool _unaryOperation) const
 {
-	if (!typeDefinition())
+	if (!typeDefinition() || !util::contains(overridableOperators, _token))
 		return nullptr;
 
 	set<FunctionDefinition const*> matchingDefinitions;