Suddenly douzens of errors using windows.h

Question

Hello,

i recently started out using visual studio c++ on my windows 10 machine because i wanted to code on the WINAPI. Unfortunately i noticed a weird behavior of MSVC++. I had my code compiling running perfectly with windows.h included. Now the exact thing i did to cause the weird behavior is changing the line:

cout << "entry: " << hex << (DWORD)((parameters*)loaderDest + 1) << endl;

to

cout << "entry: " << hex << (PVOID)((parameters*)loaderDest + 1) << endl;

and then back again. Suddenly i got 1144 Errors. They seem to be somewhat related to the typedefs in windows.h. For example suddenly hovering over DWORD gives

typedef <error-type> DWORD(<error-type>).

I don't understand this syntax but watching other error messages it seems like DWORD is interpreted as a function. If i go to the typedef it jumps to

typedef DWORD (WINAPI *PTHREAD_START_ROUTINE)(LPVOID lpThreadParameter);

Now last time i had a very similar problem when including stdio.h and then again removing it. That time i got douzens of errors when including <iostream> and i ended up simply uninstalling and installing MSVC++ which fixed it. But since this problem seems to reappear i wanted to ask what causes this behavior? Could it be that MSVC++ sometimes adds #defines to my file which alter the behavior of windows.h?

Tanks for help.

Answer 1

Hello,
I'm sorry I cannot reproduce your problem. I think you must have done more than only change the line and change it back.

Nevertheless I remember I had questionable errors with windows.h before too. The errors resulted because of other include files or a special project type.
You could try the following:

1. change the order of #include
2. for cout, do you use the standard library std::cout or the "old" cout - I've seen differences there too. Search for using namespace std for example. When you use cout, it can be different from std::cout. Define cout explicitly.
3. What kind of project do you use in VS? As far as I remember, there can be differences between a console app and a GUI MFC app (e.g. in MFC you don't include windows.h by yourself, you should VS handle the include).
4. change DWORD to unsigned long.

Regards, Guido