Structs with unnamed union fields

[JBetz]

How do I generate a type definition for structs with unnamed unions?

For example:

typedef struct clap_window {
    const char * api;
    union {
        clap_nsview cocoa;
        clap_xwnd x11;
        clap_hwnd win32;
        void * ptr;
    }
} clap_window_t;

Giving the field an arbitrary name doesn't work, nor does giving it no name. And when I generated bindings using c2hsc, the second field was omitted entirely.

#starttype struct clap_window
#field api , CString
#field window.cocoa , clap_nsview
#field window.x11 , clap_xwnd
#field window.win32 , clap_hwnd
#field window.ptr , Ptr ()
#stoptype

error: ‘struct clap_window’ has no member named ‘window’

#starttype struct clap_window
#field api , CString
#field .cocoa , clap_nsview
#field .x11 , clap_xwnd
#field .win32 , clap_hwnd
#field .ptr , Ptr ()
#stoptype

error: expected identifier before ‘.’ token