How to print a Vec?

I tried the following code:

fn main() {
    let v2 = vec![1; 10];
    println!("{}", v2);
}

But the compiler complains:

error[E0277]: std::vec::Vec doesn't implement std::fmt::Display
--> src/main.rs:3:20
|
3 | println!("{}", v2);
| ^^ std::vec::Vec cannot be formatted with the default formatter
|
= help: the trait std::fmt::Display is not implemented for std::vec::Vec
= note: in format strings you may be able to use {:?} (or {:#?} for pretty-print) instead
= note: required by std::fmt::Display::fmt


Does anyone implement this trait for Vec?

let v2 = vec![1; 10];
println!("{:?}", v2);

{} is for strings and other values which can be displayed directly to the user. There's no single way to show a vector to a user.

The {:?} formatter can be used to debug it, and it will look like:

[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]


Display is the trait that provides the method behind {}, and Debug is for {:?}

Stack Overflow Q#30320083, score: 235