error[E0282]: type annotations needed for `Vec<_>`
  --> $DIR/vector-no-ann.rs:2:9
   |
LL |     let _foo = Vec::new();
   |         ^^^^   ---------- type must be known at this point
   |
help: consider giving `_foo` an explicit type, where the type for type parameter `T` is specified
   |
LL |     let _foo: Vec<T> = Vec::new();
   |             ++++++++

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0282`.