Function gmsh_sys::gmshModelGeoAddVolume

pub unsafe extern "C" fn gmshModelGeoAddVolume(
    shellTags: *mut c_int, 
    shellTags_n: usize, 
    tag: c_int, 
    ierr: *mut c_int
) -> c_int

Add a volume (a region) defined by one or more shells shellTags. The first surface loop defines the exterior boundary; additional surface loop define holes. If tag is positive, set the tag explicitly; otherwise a new tag is selected automatically. Return the tag of the volume.