List contains not working with string literal variable

help
1

Hello, I'm getting started with learning Rust and I have a question about &str.

I have a list:

let available_toppings = ["mushroom", "pickle", "onion"];

on which I'm trying to run the contains method. This works when I use the string literal "olive" directly like:

if available_toppings.contains(&"olive")
...

but doesn't work when I declare a variable tfor &str and then use it in contains:

let requested_topping: &str = "olive"
if available_toppings.contains(requested_topping)
...

Can someone help me understand why the second example doesn't work ?

2

&"olive" has type &&str, but requested_topping has type &str.

3

Does that mean &"olive" is a reference to a string literal and not actually a string literal itself ?

4

Basically, yes. &"olive" (type &&str) is a reference to "olive". "olive" is a string literal (type &str) and technically a reference to the underlying buffer contains the characters (type str)

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5

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