WIP input type cycle detection

Author: wravery

include/SchemaLoader.h

@@ -106,6 +106,7 @@ struct InputType
 	InputFieldList fields;
 	std::string_view description;
 	std::unordered_set<std::string_view> dependencies {};
+	std::vector<std::string_view> forwardDeclarations {};
 };
 
 using InputTypeList = std::vector<InputType>;

samples/today/schema.today.graphql

@@ -184,3 +184,11 @@ input ThirdNestedInput {
 input FourthNestedInput {
     id: ID!
 }
+
+#input IncludeNullableSelfInput {
+#    self: IncludeNullableSelfInput
+#}
+#
+#input IncludeNonNullableListSelfInput {
+#    selves: [IncludeNonNullableListSelfInput!]!
+#}

src/SchemaLoader.cpp

@@ -388,6 +388,7 @@ void SchemaLoader::reorderInputTypeDependencies()
 			});
 	});
 
+	std::unordered_set<std::string_view> forwardDeclared;
 	std::unordered_set<std::string_view> handled;
 	auto itr = _inputTypes.begin();