`cargo new --edition 2018`?

[japaric]

cargo new creates a new project for the 2015 edition. If you want to use the 2018 features like not having to type extern crate foo to be able to import foo::bar then you have to add this to your Cargo.toml:

cargo-features = ["edition"]

[package]
edition = "2018"
# ..

Would it make sense to add an --edition flag to cargo new to indicate which edition the project will use? For example, cargo new --edition 2018 would create a project with a Cargo.toml that includes package.edition = "2018"

Please avoid discussing whether cargo new should default to the 2018 edition. That's a separate issue and should be discussed separately.

[MggMuggins]

Does this flag in Cargo.toml change how your crate is used as a dependency? AKA, does specifying edition = "2018" mean that someone using a project with edition = "2015" or no edition cannot use my crate as a dependency?

[ehuss]

@MggMuggins Dependencies will use the edition that they declare, regardless of the edition in your root package. It should be safe to use 2018 dependencies in a 2015 package.