Async MQTT client
Simple and rather basic C++ implementation of an MQTT client (v3.1.1) for use anywhere (embedded or full OS system). Only includes the App layer and the user is responsible for any network plumbing. This enables the underlying layer to be TCP, UDP, TLS or any other transport layer you can think of.
For now it should only support QoS = 0 but the idea is to implement all the features more or less.
Includes a very simple POSIX cli tool to perform some basic testing.