oop - Add an extension/method to all objects in Swift -

in objective-c, objects can treated type id, , objects inherit nsobject. (blocks don't, that's exception.)

thus it's possible create objective-c category extends objective-c objects. (ignoring blocks)

in objective-c, created extension nsobject uses associated objects optionally attach dictionary nsobject. enabled me implement methods setassocvalue:forkey: , assocvalueforkey: makes possible attach key/value pair nsobject. useful in lots of circumstances.

it makes possible add stored properties category, example. write getter/setter uses associated value methods attach stored object, , away go.

it makes possible attach values existing system objects @ runtime. can hang data or blocks of code on buttons, or whatever need do.

i'd same thing in swift.

however, swift not have common base class objects objective-c does. anyobject , any protcols.

thus,

extension anyobject 

won't compile.

i'm @ loss "attach" setassocvalue:forkey: , assocvalueforkey: methods in swift.

i create base class extension, defeats point of using extension. make base object objective-c nsobject, means objects have nsobjects, , swift objects not nsobjects default.

(btw, question applies both mac os , ios platforms)

no. you've pretty answered own question--swift objects don't have base class, , real way around inherit nsobject.