Function gr_test_approx_binary_op 

pub unsafe extern "C" fn gr_test_approx_binary_op(
    R: *mut gr_ctx_struct,
    op: gr_method_binary_op,
    R_ref: *mut gr_ctx_struct,
    rel_tol: gr_srcptr,
    state: *mut flint_rand_struct,
    test_flags: c_int,
) -> c_int