[Solved] Prototype already declared

[BarryG]

[Edit] Solved. That line was in an IncludeFile, which I accidentally included twice with a small source change today. Hence why searching my sources didn't show any duplicates.

I hope this info helps someone else in future, because searching these forums for "Prototype already declared" had no obvious matches for this issue.

And now, my original post for posterity:

I'm getting a "Prototype already declared" error for my app today, seemingly out of the blue. For this line:

Code: Select all

Prototype DwmGetWindowAttribute_(hWnd,dwAttribute.l,*pvAttribute,cbAttribute.l)

But when I search all my source files for "DwmGetWindowAttribute", that line is the ONLY single place it's found. So what's happening?

If I comment out the line, then my app doesn't compile with a different error ("Structure not found: DwmGetWindowAttribute_.")

But my concern is why the Prototype line is now suddenly throwing an error, when I've been using it without problems for months?

[Little John]

[Edit] Solved. That line was in an IncludeFile, which I accidentally included twice with a small source change today.

I never use IncludeFile, but only XIncludeFile. I wonder whether there is need for the IncludeFile statement at all. Perhaps it should be declared deprecated.

[BarryG]

I was thinking about that too, LJ. But then I realised sometimes IncludeFiles are not procedures, but just little code snippets that you may want to include at that point, similar to a macro insertion. So yeah, both types are needed.

[Little John]

The files that I personally use with XIncludeFile only contain definitions (constants, structures, prototypes), as well as macros and procedures (mostly inside of modules).
However, I see now. Generally speaking, you are right, of course.

[skywalk]

I struggle to justify naked IncludeFile's. This and EnableExplicit OFF are recipes for sour code.

[Tenaja]

I struggle to justify naked IncludeFile's. This and EnableExplicit OFF are recipes for sour code.

+1