I would like to enable a feature for the entire Cargo project. For example, I would like to add #![feature(non_ascii_idents)]to each source file. Is there a place to list them in Cargo.toml?
#![feature(non_ascii_idents)]
Cargo.toml
No, although you do not add functions to each source file; they are attributes of the box. That is, you install them on a box, and not on each module.