Thread: iso c++ forbids forward references to 'enum'

Hi,

I am still getting to know native code.

I am trying to include libswscale into my c++ project using extern C like I have already with libavcodec but the compiler complains of an error in swscale.h when I include in my c++ file - I have tried to use a c file as well but it tells me iso c++ forbids forward references to 'enum' because some of the function declarations in the header file contain references to enum.

My own research suggests it may have something to do with using c++11 which I think I am using in my project.

Is there anything I can do to fix this and include swscale.h without errors so I can resize an AVFrame* in my project using libswscale?

My project is a Tizen app with a native module and seems to have to use flags -c and -std=gnu++11 to compile without errors usually.

Thanks in advance.

Thanks for your response.

I am including the swscale.h header file (by linking the folder which includes third party header files I use). It just errors when building and show some functions in that header file as invalid because of the enums being passed in the functions - a example function in that header file is below..

Code:

int sws_isSupportedOutput(enum  pix_fmt);

Hi,

The error when I include swscale.h and try to use a function in it is

third_party/include/libswscale/swscale.h:205:60: error: ISO C++ forbids forward references to 'enum' types
struct SwsContext *sws_getContext(int srcW, int srcH, enum PixelFormat srcFormat,
^

I have just noticed If I try to build still including the library without using the function or including the header I get an error about the library telling me I must use --pnacl-allow-native

Thanks for that answer, it helped fix the problem