How do I interface D to a C library based on a DLL?

[Frits van Bommel]

Christopher Grantham wrote:
> Sorry, should have included the 'test.d' file...very n00bish, but its 
> the most simple way to know the API library is working:
> 
> #!J:/dmd/bin/dmd.exe -run
> 
> import std.stdio;
> import std.c.windows.windows;
> 
> import OrcFxAPI;
[snip]
> 
> As you can see, I'm assuming the converted header becomes a D module 
> with the filename as the module name (minus the '.d' extension)...
> I'm probably going about it all wrong or something, so feel free to 
> correct me, I could use the constructive criticism...

The naming of the converted header doesn't matter much, though 
consistency with the C name is probably a good thing.

You may want to post your OrcFxApi.{h,d} files (or links to them) if you 
need help translating.
Or you could just see if bcd (http://dsource.org/projects/bcd) can 
translate it automatically.

At first glance, since the errors you get are all "Previous Definition 
Different", I'd guess you were compiling your translated header and 
linking to it. And you're not using extern {} to stop inclusion of 
symbols already defined in the actual library.
If you're using a raw command line, not compiling your module at all may 
work (if everything needed to use it can be linked in from the C library).
If you're using (re)build, putting "version(build) pragma(nolink);" in 
the .d file or renaming it to .di may do the trick.
Otherwise, try wrapping your translated header (except any #defines 
translated to constants or functions) in an "extern {}" (as well as the 
normal "extern(C) {}").

If none of the above works, post your .h and .d/.di files and someone 
may be able to help.