Use rvalue or delete copy/move/assign on some classes.

[lmroz]

I've been writing in c++ (very) long time ago, but for me it looks like you can make copy of Config or just keep reference to it (and possibly other object) for later use and I expect after request handling is finished their content is no longer valid (like bare reference to rpc::ConfigMap). Accessing this might cause access violation exception.

[mkleina]

Maybe good idea would be to test if this scenario actually takes place and then paste some code for others so someone will be able to reproduce it?

[mkleina]

I don't checked whole snap-plugin-lib-cpp code, but if I understand correctly, author took into account the Config lifetime, as you can read in src/snap/config.h:

class Config {
 public:
   /**
   * A config is immutable, and is always passed _to_ a Plugin Author's plugin,
   * If one is constructed manually, any reads will be attempt to do `gets`
   * against an unallocated pointer.  Deleting this constructor will block, at
   * compile time, the ability to construct and use an incomplete config.
   */
  Config() = delete;

  /**
   * This library controls the lifetime of not only the Plugin::Config type,
   * but also the rpc::ConfigMap it contains. This allows us hold a reference to
   * the contained rpc::ConfigMap without using smart pointers or explicitly
   * managing memory.
   */
  explicit Config(const rpc::ConfigMap&);

  ~Config();

  bool get_bool(const std::string& key) const;
  int get_int(const std::string& key) const;
  std::string get_string(const std::string& key) const;

 private:
  const rpc::ConfigMap& rpc_map;
};

[mkleina]

@lmroz