If you use C library or API, I think you should learn C language. If you know C, you would be able to solve such a problem yourself. If you wrap C library/API without knowing C language, you might write unsafe code.
It seems there people trying to use C library/API with Nim without knowing C language. If we don't tell them to learn C, they will keep asking for C questions. `clipboard_c` is an incomplete struct type and you always use pointer to `clipboard_c`, but never declare `clipboard_c` variable. Also you cannot use `sizeof(clipboard_c)`. You can use functions in the library with pointer to incomplete struct.
