I often see Struct used to create some one-off anonymous data structure
like so:
> person = Struct.new(:name, :age)
=> #<Class:0x007fc6c89112e8>
> person.new("Alice", 33)
=> #<struct name="Alice", age=33>This will often get the job done, but on its own the resulting data structure doesn't tell us as much as it could.
We can say more with a named struct:
Struct.new("Person", :name, :age)
=> Struct::Person
> Struct::Person.new("Bob", 24)
=> #<struct Struct::Person name="Bob", age=24>When the first argument is a string that can be converted to a constant,
then we'll get a named struct that is subclassed under Struct.
We can also assign the struct initialization to a constant to do a similar thing:
> Person = Struct.new(:name, :age)
=> Person
> Person.new("Jerry", 45)
=> #<struct Person name="Jerry", age=45>