cr0wbar's Rust course - Beyond the basics: quiz

Question 1

Will the following code compile?

fn identity(t: T) -> T {
t
}

fn main() {
println!("{} {:?} {}", identity(5), identity([1,2,3]), identity("hello"))
}

Yes No

Question 2

Why does the following function successfully compile?

fn f() -> &'static str {
"hello"
}

The function f() is never used
The lifetime of the returned string in f() is guaranteed to be valid
It doesn't

Question 3

Fill in the blank so that the struct defined below is explicitly cloneable.

#[derive()]
struct S {
string: String,
opt: Option,
res: Result
}

Question 4

True or false:

The lifetime of a reference is independent of its original variable's lifetime.

True False

Question 5

Will the following compile?

fn f<'a, T>(arr: &'a Vec< T >) -> &'a T where T: Copy {
&arr[0]
}

fn main() {
let mut v = vec![];
v.push(String::from("This is a string!"));
println!("{}", f(&v))
}