Rust's equivalent of Python's ljust() string method

Question

I need to left-justify a &str in Rust.

In Python, I would do:

f"{spam}: {eggs}".ljust(curses.COLS - 1)

How can I do this idiomatically in Rust?

Answer 1

Formatting macros such as println!, write! and format! offer this functionality. Have a look at https://doc.rust-lang.org/std/fmt/#fillalignment and https://doc.rust-lang.org/std/fmt/#width.

• {:5} specifies a minimum width of 5
• {:-<5} left-aligns to five digits and fills with -
• {1:0$}: "The value for the width can also be provided as a usize in the list of parameters by adding a postfix $, indicating that the second argument is a usize specifying the width."