In C++ case usually is the outcome of compiling everything from source, not using binary libraries for dependencies, binary caching, pre-compiled headers, incremental compilation and linking.

Some of the items tend to be rather sub-optimal in UNIX based C++ compilers.

Using Visual C++ or C++ Builder with pre-compiled headers, or modules nowadays, working only on the main application, with everything else compiled as DLLs, COM, or packages (C++ Builder specific), incremental compiler, incremental linking, hot code reloading, is rather fast for the typical compile-debug-fix workflow.

The comment I responded to said "Rust claims to be a fast language, but compiling, even without optimizations on, takes ages". I agree that if you skip compiling and just reuse stuff that was already compiled, then the time it takes to compile C++ is fast, but that's not really what was being discussed.