Swift use c struct

Question

Sorry for the title, I can\'t find words to describe my question in few words.

I already know that swift can use struct written in c. For example

In Bridging-Hea

Answer 1

After change my question, I got an answer.

When the struct implements in hidden, this is called "opaque"

so I can use COpaquePointer.

var pointer: COpaquePointer = COpaquePointer.null()
// some init code.
init_pointer(pointer);