Reference counting is a GC algorithm from CS point of view, it doesn't matter if it is compile time or runtime.

Additionally there isn't a single ARC implementation that is 100% compile time, that when looking at the generated machine code has removed all occurrences from RC machinery.

But common, collouqialy "Garbage Collection" as a language feature refers to a run time garbage collector.

Saying that the language has GC just because it has opt-in reference counting is needlessly pedantic

Knowlege gets taught in specific institutions exactly because street knowledge is quite often incorrect, like in this case, spreading urban myths based in shaky foundations.

While I am usually the one that also goes in and correct people incorrectly calling RC not a GC, the important distinction here is that Rust (and C++) has the necessary language constructs to be able to implement ref counting entirely as a library.

Which is a performance bottleneck, as the compiler is blind to library implementations and cannot optimise accordingly.

Also implementation has nothing to do with CS definition, there are tracing GC libraries for C as well.

I agree with your first point, and I didn't say anything contrary to your second.

My point is about crossing the misunderstanding between the "two camps".

Fair enough.