kCGImageSourceShouldCacheImmediately
A Boolean value that indicates whether image decoding and caching happens at image creation time.
Declaration
let kCGImageSourceShouldCacheImmediately: CFStringDiscussion
The value of this key is a CFBoolean. The default value is kCFBooleanFalse, which causes decoding and caching to happen only when you render the image.
Include this key in the options dictionary you pass to the functions CGImageSourceCopyPropertiesAtIndex(_:_:_:) and CGImageSourceCreateImageAtIndex(_:_:_:).