Rust 1.58.0

Being able to use formatting patterns similar to python sounds really awesome. It makes formatting with long formatting strings really a lot more expressive and more readable.

&gt; Format strings can only capture plain identifiers, not arbitrary paths or expressions.<p>Why?

This is a nice step.<p>Now they should allow expressions in addition to just names and apply it to all string literals.

Nice work! Looks like I have some code updates to do.

index or format specs are ok, but capturing variables is a bad idea, visually bloats the string, it becomes unreadable