If you want to use something like this right now (with a threadsafe bonus) concurrent-ruby has some useful specialized structs that offer similar behavior: * I

If you want to use something like this right now (with a threadsafe bonus) concurrent-ruby has some useful specialized structs that offer similar behavior: * ImmutableStruct: Immutable struct where values are set at construction and cannot be changed later. * MutableStruct: Synchronized, mutable struct where values can be safely changed at any time. * SettableStruct: Synchronized, write-once struct where values can be set at most once, either at construction or any time thereafter. https://github.com/ruby-concurrency/concurrent-ruby https://github.com/ruby-concurrency/concurrent-ruby