custom_structs_example.rb

module Entities
  class User < ROM::Struct
    def name
      [first_name, last_name].join(' ')
    end
  end
end

class Users < ROM::Relation[:sql]
  schema do
    attribute :id, Types::Serial,
    attribute :first_name, Types::String
    attribute :last_name, Types::String    
  end
end

class UserRepo < ROM::Repository[:users]
  struct_namespace Entities
end

UserRepo.new(container).users.to_a # => <# Entites::User ... >
UserRepo.new(container).users.to_a.map(&:name) # => ['John Doe', ...]

😎