preprocessor #warning equivalent in Visual C++?

Question

In C# we can use #warning to show a warning in error window.
In Visual C++, #pragma message is something like that, but it just a outputs a message not a warning.

In C++ (Windows, Visual Studio, MSVC) is there a way to show a warning to user purposely?

I tried #warning DEBUG is defined which works in some other compilers, but not MSVC.
It gives me this error:

error C1021: invalid preprocessor command 'warning' AecProject stdafx.h 49

Answer 1

In gcc, #warning works fine in the way that you would expect (i.e. like #error it outputs a message at compile time, but does not cause the compilation to terminate)

It seems that #warning is not available in Visual Studio. Instead you can try experimenting with #pragma warning although this does not emit a message but allows the settings for compiler messages to be altered. The syntax for this is more complex and can be found here