Custom Parsers While the parsers included in the library will handle a broad number of use-cases, the __basic_parser__ interface can be subclassed to implement custom strategies for storing parsed results: the basic parser processes input buffers into elements according to the HTTP/1 protocol specification, while the derived class decides what to do with those elements. Custom parsers will work with all of the HTTP stream read algorithms, as those algorithms use only the basic parser interface. Some use cases for implementing custom parsers are: * Inspect incoming header fields and keep or discard them. * Use a container provided by an external interface. The basic parser uses virtual functions. To declare your user-defined parser, derive from __basic_parser__ and implement all the required virtual functions. A declaration for the derived class may look like this: