Added is_interned method which returns a bool

[DanielJoyce]

• Returns true if value already interned.
• Added simple test as well.

[DanielJoyce]

Closes #45

[droundy]

suggestion: You can remove the From constraint for this method.

Suggested change

	pub fn is_interned<'a, Q: ?Sized + Eq + Hash + 'a>(val: &'a Q) -> bool
	where
	&'static T: Borrow<Q> + From<&'a Q>,
	pub fn is_interned<'a, Q: ?Sized + Eq + Hash + 'a>(val: &'a Q) -> bool
	where
	&'static T: Borrow<Q>,

[DanielJoyce]

If I do, then I need to specify generic bounds on line 72:

type annotations needed
cannot satisfy `_: std::cmp::Eq`rustc[Click for full compiler diagnostic](rust-analyzer-diagnostics-view:/diagnostic%20message%20%5B24%5D?24#file%3A%2F%2F%2Fhome%2Fdanieljoyce%2Fgit%2Fgeneral%2Finternment%2Fsrc%2Fintern.rs)
intern.rs(204, 9): required by a bound in `Intern::<T>::is_interned`
intern.rs(72, 19): consider specifying the generic argument: `::<T>`

[DanielJoyce]

Okay, one sec.

[DanielJoyce]

If I remove the From<> bounds on T, then it requires dismbiguation per the above error message.

[DanielJoyce]

If I move the is_interned to the impl<T: Eq + Hash + Send + Sync + 'static + ?Sized> Intern<T> { block, then

 let _ = Intern::new("Fortunato");
    assert!(Intern::is_interned(&"Fortunato"));
    assert!(Intern::is_interned("Fortunato"));

Both check as valid, but when I run the test, assert!(Intern::is_interned("Fortunato")); fails.

[droundy]

suggestion: Could you also test if we can pass just a &str to is_interned?

Suggested change

	assert!(Intern::is_interned(&"Fortunato"));
	assert!(!Intern::is_interned(&"Montresor"));
	assert!(Intern::is_interned(&"Fortunato"));
	assert!(!Intern::is_interned("Fortunato"));
	assert!(!Intern::is_interned(&"Montresor"));
	assert!(!Intern::is_interned("Montresor"));

[DanielJoyce]

The problem is the && and & cases can't be unified trivially. Or I don't understand enough rust black magic to do so.

Basically Intern::is_interned(&"") checks Intern<&str> and Intern::is_interned("") checks Intern<str> which are different.

[droundy]

Could you fix the conflicts, and also add an entry to CHANGELOG.md?

And thanks for the contribution!

[DanielJoyce]

Whoops, will do, sorry, hadn't check back in a while. :)

[droundy]

Due to conflict, I merged this outside of github. I also made some tweaks, so please take a look!