extern(C++) and shared

[deadalnix]

I have this function :
extern(C++) void* __dsfml_start_thread(EntryPoint entryPoint, void* 
userData);

If EntryPoint is defined as follow :
alias extern(C++) void* function(void*) EntryPoint;

The function mangle in _Z20__dsfml_start_threadPFPvS_ES_

if alias extern(C++) void* function(shared void*) EntryPoint;
_Z20__dsfml_start_threadPFPvPvES_

Both demangle using c++filt in __dsfml_start_thread(void* (*)(void*), 
void*), which is what is expected.

But the definition without shared will be the only one to link successfully.

Is the mangling of shared types is consistent in C++ ? shared doesn't 
exists in C++, so I guess we should expect the same mangling in both 
cases. Unless it exists some magic on the C++ side that I'm not aware of ?