That's a mangling compression scheme (possibly tunable via gcc options), from https://github.com/gchatelet/gcc_cpp_mangling_documentation:
To save space a compression scheme is used where symbols that appears multiple times are then substituted by an item from the sequence : S_, S0_, S1_, S2_, etc ...

As to nested C++ namespaces - `extern(C++, ns1) { ... extern(C++, ns2) { ... } }` should work in a single D file.

Reply via email to