init(_:unlabeledChildren:displayStyle:ancestorRepresentation:)

Declaration

init<Subject, C>(_ subject: Subject, unlabeledChildren: C, displayStyle: Mirror.DisplayStyle? = nil, ancestorRepresentation: Mirror.AncestorRepresentation = .generated) where C : Collection

Parameters

• subject:

  The instance to represent in the new mirror.

• unlabeledChildren:

  The children to use for the mirror. The collection traversal modeled by unlabeledChildren is captured so that the resulting mirror’s children may be upgraded to a bidirectional or random access collection later. See the children property for details.

• displayStyle:

  The preferred display style for the mirror when presented in the debugger or in a playground. The default is nil.

• ancestorRepresentation:

  The means of generating the subject’s ancestor representation. ancestorRepresentation is ignored if subject is not a class instance. The default is .generated.

Discussion

You use this initializer from within your type’s customMirror implementation to create a customized mirror, particularly for custom types that are collections. The labels of the resulting mirror’s children collection are all nil.

If subject is a class instance, ancestorRepresentation determines whether ancestor classes will be represented and whether their customMirror implementations will be used. By default, the customMirror implementation of any ancestors is ignored. To prevent bypassing customized ancestors, pass .customized({ super.customMirror }) as the ancestorRepresentation parameter when implementing your type’s customMirror property.