code.rs

let a: Vec<Vec<uint>> = vec![];
let b: Vec<Vec<uint>> = a.iter().collect();

Error

012.rs:82:29: 82:47 error: type mismatch: the type `collections::vec::Vec<collections::vec::Vec<uint>>` 
  implements the trait `core::iter::FromIterator<collections::vec::Vec<uint>>`, but the trait 
  `core::iter::FromIterator<&collections::vec::Vec<uint>>` is required (expected &-ptr, found struct 
  collections::vec::Vec)
012.rs:82     let b: Vec<Vec<uint>> = a.iter().collect();
                                      ^~~~~~~~~~~~~~~~~~
error: aborting due to previous error