Question about function aliases

[FreeSlave]

On Thursday, 12 December 2013 at 11:11:55 UTC, bearophile wrote:
> Gary Willoughby:
>
>> alias void function(ClientData clientData, Tcl_Interp* interp)
>>  Tcl_InterpDeleteProc;
>>
>> extern (C) void Tcl_CallWhenDeleted(Tcl_Interp* interp, 
>> Tcl_InterpDeleteProc proc, ClientData clientData);
>
> With recent D compilers I prefer the alias with "=" and a more
> aligned colums formatting of the arguments when they don't fit
> well in a line:
>
>
> alias Tcl_InterpDeleteProc = void function(ClientData 
> clientData,
> Tcl_Interp* interp);
>
> extern(C) void Tcl_CallWhenDeleted(Tcl_Interp* interp,
>                                     Tcl_InterpDeleteProc proc,
>                                     ClientData clientData);
>
> Also, can't you add some "const" in those arguments? Is your C
> function pure? It should be nothrow.
>
> Bye,
> bearophile

I guess alias also should include extern(C) declaration i.e. the 
right way is
alias Tcl_InterpDeleteProc = extern(C) void function(ClientData 
clientData, Tcl_Interp* interp) nothrow;

So your callback on D side must have C-linkage too.
Lack of extern(C) in alias probably will not cause problem on 
Linux, but in my experience, Windows requires it otherwise you 
will get seg fault.