Try a more limited version of #126

Author: wravery

include/graphqlservice/GraphQLService.h

@@ -947,14 +947,17 @@ struct SubscriptionData : std::enable_shared_from_this<SubscriptionData>
 	const peg::ast_node& selection;
 };
 
+// Forward declare just the class type so we can reference it in the Request::_validation member.
+class ValidateExecutableVisitor;
+
 // Request scans the fragment definitions and finds the right operation definition to interpret
 // depending on the operation name (which might be empty for a single-operation document). It
 // also needs the values of the request variables.
 class Request : public std::enable_shared_from_this<Request>
 {
 protected:
 	GRAPHQLSERVICE_EXPORT explicit Request(TypeMap&& operationTypes);
-	GRAPHQLSERVICE_EXPORT virtual ~Request() = default;
+	GRAPHQLSERVICE_EXPORT virtual ~Request();
 
 public:
 	GRAPHQLSERVICE_EXPORT std::vector<schema_error> validate(peg::ast& query) const;
@@ -1025,6 +1028,7 @@ class Request : public std::enable_shared_from_this<Request>
 		const std::string& operationName, response::Value&& variables) const;
 
 	TypeMap _operations;
+	std::unique_ptr<ValidateExecutableVisitor> _validation;
 	std::map<SubscriptionKey, std::shared_ptr<SubscriptionData>> _subscriptions;
 	std::unordered_map<SubscriptionName, std::set<SubscriptionKey>> _listeners;
 	SubscriptionKey _nextKey = 0;

src/GraphQLService.cpp

@@ -1759,20 +1759,25 @@ void SubscriptionDefinitionVisitor::visitInlineFragment(const peg::ast_node& inl
 
 Request::Request(TypeMap&& operationTypes)
 	: _operations(std::move(operationTypes))
+	, _validation(std::make_unique<ValidateExecutableVisitor>(*this))
 {
 }
 
+Request::~Request()
+{
+	// The default implementation is fine, but it can't be declared as = default because it needs to
+	// know how to destroy the _validation member and it can't do that with just a forward
+	// declaration of the class.
+}
+
 std::vector<schema_error> Request::validate(peg::ast& query) const
 {
 	std::vector<schema_error> errors;
 
 	if (!query.validated)
 	{
-		ValidateExecutableVisitor visitor(*this);
-
-		visitor.visit(*query.root);
-
-		errors = visitor.getStructuredErrors();
+		_validation->visit(*query.root);
+		errors = _validation->getStructuredErrors();
 		query.validated = errors.empty();
 	}