Function pio_geo_layer_to_geojson 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pio_geo_layer_to_geojson(
    layer: *const PioGeoLayer,
    error: *mut *mut PioError,
) -> *mut PioString

Write the layer as the canonical .geo.json document: a GeoJSON FeatureCollection whose powerio_geo member states the coordinate space and the writer’s version. The text is owned by the returned handle and read with pio_string_view; release it with pio_string_release.

Safety

Pointers and handles must satisfy the crate-level safety requirements.