Real-time map matching in C/C++

We want to implement a real-time map matching algorithm for a GPS-tracker. The GPS-tracker will use an STM32 microcontroller. For this project we need a proof-of-concept: the map-matching does not need to run on the microcontroller yet (but this should be kept in mind while developing the project, as the available resources will be limited). Preferably, the algorithm should use OpenStreetMap data.