pub enum CGImage {}
pub type CGImageRef = *mut CGImage;

pub enum CGColorSpace {}
pub type CGColorSpaceRef = *mut CGColorSpace;

pub enum CGDataProvider {}
pub type CGDataProviderRef = *mut CGDataProvider;

pub enum CGFont {}
pub type CGFontRef = *mut CGFont;

pub enum CGEvent {}
pub type CGEventRef = *mut CGEvent;

pub enum CGContext {}
pub type CGContextRef = *mut CGContext;