attachedMode(of:)
Returns the propagation mode of a stored attachment you identify with a key path to a key definition that supplies a default, without retrieving it.
Declaration
func attachedMode(of keyPath: KeyPath<Keys.Type, CVAttachmentKeyDefinitionWithDefault<some CVAttachmentModePreference, some CVAttachmentValueRepresentable & Equatable & Sendable>>) -> CVAttachmentMode?Parameters
- keyPath:
A key path to a key definition that supplies a default value.
Return Value
The propagation mode of the attachment, or nil if the key isn’t attached.
Discussion
Use this method to check for the presence of a specific key without converting its value.
Because this kind of key supplies a default, reading it as a property always produces a value, whether or not the container holds an attachment for it. This method returns nil in the second case, which makes it the way to tell a stored value from a defaulted one.