> I do have a hard time to think of use cases other than embedded microcontroller work where that matters nowadays. Another example: realtime audio application

> I do have a hard time to think of use cases other than embedded microcontroller work where that matters nowadays. Another example: realtime audio applications. There are rather strict rules about what you can and cannot do in the audio callback. In particular, you must not use the system memory allocator (because it may block). Instead you have to pre-allocate memory or use real-time safe memory pools. For this reason, the vast majority of (realtime) audio code is still written in C and C++.