Q:

Print sliced vector results in "Sized is not satisfied"

I am trying to slice a vector and print it simultaneously in Rust.  This is my code:
fn main() {
    let a = vec![1, 2, 3, 4];
    println!("{:?}",  a[1..2]);
}

Error:
error[E0277]: the trait bound `[{integer}]: std::marker::Sized` is not satisfied
 --> src/main.rs:6:5
  |
6 |     println!("{:?}",  a[1..3]);
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ trait `[{integer}]: std::marker::Sized` not satisfied
  |
  = note: `[{integer}]` does not have a constant size known at compile-time
  = note: required by `std::fmt::ArgumentV1::new`
  = note: this error originates in a macro outside of the current crate

How do I print this sliced vector? 

A:

You need to use a reference; it worked for me in Rust 1.13. 
println!("{:?}", & a[1..3]);

