You might confuse rust version with rust editions. Version: 1.0.0,.., 1.50.0, 1.51.0, ... Edition: 2015, 2018, .. Versions are the compiler version you use.

You might confuse rust version with rust editions. Version: 1.0.0,.., 1.50.0, 1.51.0, ... Edition: 2015, 2018, .. Versions are the compiler version you use. Editions are more like a language dialect, and all newer compilers support all "older" editions. What versions change tend to be: - config defaults, e.g. make some warnings errors, change the default dep. resolver, etc. - syntax (in minor ways). E.g. add a new keyword for a new feature/syntax or remove a reversed but unused keyword where it's no clear that it's not needed. - improvements the the borrow checker or import system which in some edge cases could break existing code. Anyway any rust version supports all editions released up to the point in time and you can freely mix and match them between dependencies.