I want to develop openCv project in Visual Studio 2017. I downloaded the opencv pre-build libraries and made necessary settings. That is:
1) I added System Path ..
This error is caused due to a long comment about Mat. Look for mat.hpp files in your include directory of opencv (use search to find) >> go to Mat function definition >> remove the multiline comment before Mat definition.
There are two mat.hpp files in the include directory. Follow the steps in both.
Save the files. Restart Visual Studio and enjoy !!