Base.FieldSourceOCaml record field.
'record is the type of the record. 'field is the type of the values stored in the record field with name name. 'perm is a way of restricting the operations that can be used.
A record field with no restrictions.
A record that can only be read, because it belongs to a private type.
val updater :
([> `Set_and_create ], 'r, 'a) t_with_perm ->
('r -> f:('a -> 'a) -> unit) optiontype ('perm, 'record, 'result) user = {f : 'field. ('perm, 'record, 'field) t_with_perm -> 'result;}