ios - Swift - Typealias dictionary with value that implements a generic protocol -

i want typealias dictionary of string keys , values of objects/structs implements equatable protocol. wrote line of code gave me error didn't know how go on fix.

typealias storage = [string: equatable] 

i want use type [string: equatable] variable in protocol, e.g:

protocol storagemodel {     var storage: storage { set }     init(storage: storage) } 

error:

protocol 'equatable' can used generic constraint because has self or associated type requirements

can suggest solution?

generally speaking, protocol tag isn't required, protocol names first-class type names , can used directly:

typealias storage = [string:equatable] 

in case, error telling because equatable includes func == (lhs:self, rhs:self) -> bool , lhs:self, equatable can't used except constraint on generic:

class generic<t:equatable> { ... } 

without more details you're trying achieve , how you're trying use storagemodel, best can come is:

protocol matches {     typealias t     func matches(t:t) -> bool }  protocol storagemodel {     typealias t     var storage: [string:t] { set }     init(storage:[string:t]) }  extension int : matches {     func matches(target:int) -> bool {         return self == target     } }  class myclass <t:matches> {     var model = [string:t]()   } 

another possibility use generic instead of protocol:

class storagemodel <t:equatable> {     var storage: [string:t]      init(storage:[string:t]) {         self.storage = storage     } } 

from there you'll need research, dig swift manual, googling , see solves problem.