Software design ideas to deal with ownership when writing high level wrapper of C code

[giaco]

I agree that the wrapper object based solution is the only solution for the 
moment, as other solutions leveraging on generics and distinct types seems to 
not work.

here's another take that is not calling the destructor , but it will if 
<https://github.com/nim-lang/Nim/issues/23394> is solved
    
    
    type
      Ownership = enum
        Owned
        Borrowed
      
      Wrapper[T; ownership: static Ownership] = distinct T
    
    proc `=destroy`[T, ownership](val: Wrapper[T, ownership]) =
      echo "destroying ", val
    
    # ------------------------------
    
    type MyCString[ownership: static Ownership] = Wrapper[cstring, ownership]
    
    proc `$`(x: MyCString): string {.borrow.}
    
    proc main() =
      var mycstring = cast[MyCString[Owned]](alloc(11))
      let str = "helloworld"
      copyMem(mycstring.cstring, str[0].addr, str.len)
      echo mycstring
    
    main()
    
    
    Run