pub unsafe extern "C" fn igraph_sparsemat_fkeep(
A: *mut igraph_sparsemat_t,
fkeep: Option<unsafe extern "C" fn(arg1: igraph_int_t, arg2: igraph_int_t, arg3: igraph_real_t, arg4: *mut c_void) -> igraph_int_t>,
other: *mut c_void,
) -> igraph_error_t