initial matador ng commit

include/matador/object/error_code.hpp

@@ -0,0 +1,32 @@
+#ifndef OBJECT_ERROR_CODE_HPP
+#define OBJECT_ERROR_CODE_HPP
+
+#include <cstdint>
+#include <system_error>
+
+namespace matador::object {
+
+enum class error_code : uint8_t {
+  OK = 0,
+  NodeNotFound = 1,
+  NodeAlreadyExists = 2,
+  Failure,
+};
+
+class object_category_impl final : public std::error_category
+{
+public:
+    [[nodiscard]] const char* name() const noexcept override;
+    [[nodiscard]] std::string message(int ev) const override;
+};
+
+const std::error_category& object_category();
+std::error_code make_error_code(error_code e);
+std::error_condition make_error_condition(error_code e);
+
+}
+
+template <>
+struct std::is_error_code_enum<matador::object::error_code> : true_type {};
+
+#endif //OBJECT_ERROR_CODE_HPP