We provide Visual Fortran DLLs to internal and external customers who use Visual Basic, Visual C++ and Delphi. I'm trying to standardize the interface used so that we can accommodate our customers without requiring a lot of work on their part.
My inclination is to mimic the Windows API calls and require VB/Delphi to do likewise. Since both languages support such calls, this choice seems natural. Ideally, I could set up an INTERFACE block in every DLL with all of the DEC$ ATTRIBUTES, etc. preset. Once that is done, providing sample VB declarations, C++ headers, and Delphi definitions would be simplified.
I would appreciate any suggestions the user community has on dealing with these issues.