* `basic_parser` now uses pure virtual member functions instead
of the curiously recurring template pattern.
Actions Required:
* Change uses of the `basic_parser` type to omit the `Derived`
template parameter
* Classes derived from `basic_parser` no longer need to friend
the base.
* Virtual functions in the derived class may be marked `override`.
- Call the completion handler with the correct signature
- Replicate ASIO socket behavior of async operation completions
- Fix a data race between read_op and a call to stream::nread()
Signed-off-by: Damian Jarek <damian.jarek93@gmail.com>
fix#1279, close#1319
This enables users to improve compilation performance by explicitly
instantiating the stream template in another TU.
Signed-off-by: Damian Jarek <damian.jarek93@gmail.com>
close#1322
async initiating functions must return init.result.get(). Returning the
result of post caused a compilation failure for custom completion tokens.
Signed-off-by: Damian Jarek <damian.jarek93@gmail.com>