module Concurrent::SettableStruct

An thread-safe, write-once variation of Ruby’s standard ‘Struct`. Each member can have its value set at most once, either at construction or any time thereafter. Attempting to assign a value to a member that has already been set will result in a `Concurrent::ImmutabilityError`.

@see ruby-doc.org/core/Struct.html Ruby standard library ‘Struct` @see en.wikipedia.org/wiki/Final_(Java) Java `final` keyword