Return geometry type of an object, as a factor

## Usage

`st_geometry_type(x, by_geometry = TRUE)`

## Arguments

- x
object of class sf or sfc

- by_geometry
logical; if `TRUE`

, return geometry type of each geometry,
else return geometry type of the set

## Value

a factor with the geometry type of each simple feature geometry
in `x`

, or that of the whole set