refactor: simplify get_height_of_terminal() and get_width...

[muzimuzhi]

The eminence/terminal-size#41 PR mentioned in comments of get_(height|width)_of_terminal() (added by c36ca33)

dust/src/main.rs

Lines 83 to 91 in b636086

	fn get_height_of_terminal() -> usize {
	// Simplify once https://github.com/eminence/terminal-size/pull/41 is
	// merged
	terminal_size()
	// Windows CI runners detect a terminal height of 0
	.map(|(_, Height(h))| max(h as usize, DEFAULT_NUMBER_OF_LINES))
	.unwrap_or(DEFAULT_NUMBER_OF_LINES)
	- 10
	}

has been merged and shipped since terminal-size v0.2.2. As we're using terminal-size v0.2.6 now, it's time to simplify them.

dust/Cargo.lock

Lines 766 to 768 in 38c4d23

	[[package]]
	name = "terminal_size"
	version = "0.2.6"

Not sure if I made it to the most simplified form, as I can hardly speak Rust.

cc @Lucretiel

[Lucretiel]

I think my original idea was that we'd just use the Height and Width types directly, rather than casting to usize. That was previously impossible in the absence of those traits.

[muzimuzhi]

Then that's out of my current Rust knowledge. Sorry, I'm closing this PR.

[bootandy]

I think its easier to convert to usize as I start doing math with it. eg: For height I use it to work out how many rows I can have displayed on the terminal.

I'd be happy to accept this pr as I think using .into() is slightly cleaner.