std::vec!

( $ ( $ x : expr ) , * ) => (
{
let xs : $ crate :: boxed :: Box < [ _ ] > = $ crate :: boxed :: Box :: new (
[ $ ( $ x ) , * ] ) ; $ crate :: slice :: SliceExt :: into_vec ( xs ) } ) ; (
$ ( $ x : expr , ) * ) => ( vec ! [ $ ( $ x ) , * ] )

Creates a Vec containing the arguments.