Swift Struct's Reference Count -

i have question struct

in wwdc2016, session recommend use sturct (value type)

but if structs have 3 more inline variable words, struct must manage reference count store large value heap

then question is
when struct have 3 struct , each struct have 2 or 3 struct or value type

i want know how works whether using reference count or not in situation

below example of structs

struct viewmodel {      var titlemodel: titlemodel      var contentmodel: contentmodel      var layoutmodel: layoutmodel }  struct titlemodel {      var text: string      var width: float      var height: float }  struct contentmodel {      var content: string      var width: float      var height: float }  struct layoutmodel {      var constant: float      var multiply: float } 

structures , enumerations have value-semantics. there no notion of reference count, because passed copying. members may pointers reference-types, pointer copied. long don't have reference-type in structure, don't need worry reference counting.

sure, 1 may argue swift internally uses copy-on-write optimizations using reference-types disguised structures (eg. array, dictionary etc.), implement value-semantics.