Using @import in objective C in conjunction with __cplusplus

Question

When I try to compile an Objective C++ file (.mm) that is linked to a file that uses the new @import directive, I get some errors. Currently, my only solution is to replace

Answer 1

In my case I needed to use OpenCV in my application.

I have solved this problem by adding

-fcxx-modules (Objective C++) manually to "Other C++ Flags"

(Build Settings/ Apple Clang - Custom Compiler Flags/ Other C++ Flags)

or

-fmodules (Objective C) to "Other C Flags"

(Build Settings/ Apple Clang - Custom Compiler Flags/ Other C Flags)

And also I needed to put import the opencv.hpp before any Apple's headers to fix errors of Expected identifier in opencv library. For example in Prefix.pch I organized it that way:

#ifdef __cplusplus
#include 
#endif

#import  

I am using:

• Xcode - 11.3
• CocoaPods - 1.9.1
• OpenCV2 - 4.3.0