code quality: deleted copy assignment operators

src/QR.hpp

@@ -32,6 +32,7 @@ namespace massivedynamic {
 			QR(const QR&&)           = delete;
 			QR(QR&)                  = delete;
 			~QR()                    = default;
+			QR& operator=(const QR&) = delete;
 
 			void render(Format format);
 

src/Renderer.hpp

@@ -14,6 +14,7 @@ class Renderer {
 		Renderer(const Renderer&&)           = delete;
 		Renderer(Renderer&)                  = delete;
 		virtual ~Renderer()                  = default;
+		Renderer& operator=(const Renderer&) = delete;
 
 		virtual void render(const std::string& filename) = 0;
 };