如何从数字中解析BigInt？(How to parse BigInt from the num crate?)

如何从数字中解析BigInt？(How to parse BigInt from the num crate?)

我正在尝试使用BigInt 。 我的代码是这样的：

extern crate num; use num::bigint::BigInt; ... println!("{}", from_str::<BigInt>("1")); //this is line 91 in the code

在我的Cargo.toml文件中，我有以下内容：

[dependencies] num = "0.1.30"

我所做的似乎与本文档中的内容相符， 也是本文档 ，也是Stack Overflow的答案 。

但是我收到以下错误：

Compiling example v0.1.0 (file:///C:/src/rust/example) src\main.rs:91:20: 91:38 error: unresolved name `from_str` [E0425] src\main.rs:91 println!("{}", from_str::<BigInt>("1"));

I am trying to use BigInt. My code is like this:

extern crate num; use num::bigint::BigInt; ... println!("{}", from_str::<BigInt>("1")); //this is line 91 in the code

In my Cargo.toml file I have the following:

[dependencies] num = "0.1.30"

What I did seem to match what was said in this document, also this document and also an answer here on Stack Overflow.

However I got the following error:

Compiling example v0.1.0 (file:///C:/src/rust/example) src\main.rs:91:20: 91:38 error: unresolved name `from_str` [E0425] src\main.rs:91 println!("{}", from_str::<BigInt>("1"));

最满意答案

想通了，看起来像当前的语法是：

"8705702225074732811211966512111".parse::<BigInt>().unwrap();

更好的是，请执行以下操作：

match "8705702225074732811211966512111".parse::<BigInt>() { Ok(big) => { ...

Figured out, seem like the current syntax is:

"8705702225074732811211966512111".parse::<BigInt>().unwrap();

Better yet, do the following:

match "8705702225074732811211966512111".parse::<BigInt>() { Ok(big) => { ...