不稳定库功能 "core" 问题的解决方法是什么?

What is the workaround for unstable library feature "core" issue?

我正在尝试在 Rust 中将大整数相加:

extern crate core;
use core::ops::Add;
use num::bigint::{BigInt};
use num::integer::Integer;
...
let mut big = "8705702225074732811211966512111".parse::<BigInt>().unwrap();
let one = "1".parse::<BigInt>().unwrap();
big = big.add(&one);

我收到以下错误:

src\main.rs:3:1: 3:19 error: use of unstable library feature 'core': the libcore library has not yet been scrutinized for stabilization in terms of structure and naming (see issue #27701)
src\main.rs:3 extern crate core;

目前有解决办法吗?还是暂时完全不可行?

您应该能够使用 std::ops::Add 特征而不是 core::ops::Add

use std::ops::Add;