Function igraph_vector_char_binsearch_slice 

pub unsafe extern "C" fn igraph_vector_char_binsearch_slice(
    v: *const igraph_vector_char_t,
    what: c_char,
    pos: *mut igraph_int_t,
    start: igraph_int_t,
    end: igraph_int_t,
) -> igraph_bool_t