建立一個新專案

A new project created with Cargo is configured to use the latest edition by default:

$ cargo new foo
    Creating binary (application) `foo` package
note: see more `Cargo.toml` keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
$ cat foo/Cargo.toml
[package]
name = "foo"
version = "0.1.0"
edition = "2024"

[dependencies]

該 edition = "2024" 設定會將您的軟體包組態為使用 Rust 2024 版次進行編譯。無需進行其他額外組態！

You can use the --edition <YEAR> option of cargo new to create the project using some specific edition. For example, creating a new project to use the Rust 2018 edition could be done like this:

$ cargo new --edition 2018 foo
    Creating binary (application) `foo` package
note: see more `Cargo.toml` keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
$ cat foo/Cargo.toml
[package]
name = "foo"
version = "0.1.0"
edition = "2018"

[dependencies]

不必擔心誤用了無效的年份作為版次； cargo new 命令不會接受無效的版次年份值：

$ cargo new --edition 2019 foo
error: invalid value '2019' for '--edition <YEAR>'
  [possible values: 2015, 2018, 2021, 2024]

  tip: a similar value exists: '2021'

For more information, try '--help'.

You can change the value of the edition key by simply editing the Cargo.toml file. For example, to cause your package to be built using the Rust 2015 edition, you would set the key as in the following example:

[package]
name = "foo"
version = "0.1.0"
edition = "2015"

[dependencies]