These functions come from OGR C API's OGR_L_*
namespace.
val t : t Ctypes.typ
val t_opt : t option Ctypes.typ
val get_name : t ‑> string
val get_geom_type : t ‑> Geometry.wkb_t
val get_spatial_filter : t ‑> Geometry.t
val set_spatial_filter : t ‑> Geometry.t ‑> unit
val set_spatial_filter_rect : t ‑> float ‑> float ‑> float ‑> float ‑> unit
val set_attribute_filter : t ‑> string ‑> unit
val reset_reading : t ‑> unit
val set_next_by_index : t ‑> int ‑> unit
val delete_feature : t ‑> int ‑> unit
val get_layer_defn : t ‑> Feature.Defn.t
val get_spatial_ref : t ‑> Spatial_reference.t option
val get_feature_count : t ‑> int ‑> int
val get_extent : t ‑> int ‑> Geometry.envelope_t
val test_capability : t ‑> string ‑> bool
val create_field : t ‑> Field.Defn.t ‑> int ‑> unit
val delete_field : t ‑> int ‑> unit
val reorder_fields : t ‑> int list ‑> unit
val reorder_field : t ‑> int ‑> int ‑> unit
val alter_field_defn : t ‑> int ‑> Field.Defn.t ‑> int ‑> unit
val start_transaction : t ‑> unit
val commit_transaction : t ‑> unit
val rollback_transaction : t ‑> unit
val reference : t ‑> int
val dereference : t ‑> int
val get_ref_count : t ‑> int
val sync_to_disk : t ‑> unit
val get_fid_column : t ‑> string
val get_geometry_column : t ‑> string
val set_ignored_fields : t ‑> string option list ‑> unit