add GL/Buffer

common/factory.hh

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "nf7.hh"
+
+#include "common/future.hh"
+
+
+namespace nf7 {
+
+template <typename T>
+class Factory : public nf7::File::Interface {
+ public:
+  using Product = T;
+
+  Factory() = default;
+  Factory(const Factory&) = delete;
+  Factory(Factory&&) = delete;
+  Factory& operator=(const Factory&) = delete;
+  Factory& operator=(Factory&&) = delete;
+
+  virtual Product Create() noexcept = 0;
+};
+
+template <typename T>
+using AsyncFactory = Factory<nf7::Future<T>>;
+
+}  // namespace nf7