Cows. Cows everywhere.

[shanecelis]

Great project. I saw an opportunity to alloc less. This PR changes input from a String to a Cow<'a, str> and the implementation for &'a str to Into<Cow<'a, str>> which will cover &str as before and String and Cows and makes the necessary changes to support that. No usage change for the end user, just broader support and less allocs.

As an aside, I added print statements to the dynamic_colors example.

[kpcyrd]

Suggested change

	#[allow(unused_mut)]
	#[allow(unused_assignments)]
	let mut tty = false;
	#[cfg(feature = "tty")]
	{
	tty = atty::is(atty::Stream::Stdout);
	}
	let tty = if cfg!(feature = "tty") {
	atty::is(atty::Stream::Stdout)
	} else {
	false
	};

[shanecelis]

Good idea. I like this better than mine but it doesn't compile. This compiles:

        let tty = if cfg!(feature = "tty") {
            #[cfg(feature = "tty")]
            {
            atty::is(atty::Stream::Stdout)
            }
            #[cfg(not(feature = "tty"))]
            false
        } else {
            false
        };

But we can clean it up further to this:

        let tty = {
            #[cfg(feature = "tty")]
            {
                atty::is(atty::Stream::Stdout)
            }
            #[cfg(not(feature = "tty"))]
            false
        };

And sorry there are some commits that I didn't mean to put into this PR.

[kpcyrd]

You could also use

use std::io::{self, IsTerminal};
let tty = io::stdout().is_terminal();

that was very recently introduced in the Rust 1.70.0 std library.

[shanecelis]

Could use that and drop the atty dependency.