class FFI::StructLayout::Mapped

def get(ptr)
  type.from_native(@orig_field.get(ptr), nil)
end

def initialize(name, offset, type, orig_field)
  super(name, offset, type)
  @orig_field = orig_field
end

def put(ptr, value)
  @orig_field.put(ptr, type.to_native(value, nil))
end