(vector-of t) (vector-of t & elements)
Creates a new vector of a single primitive type t, where t is one of :int :long :float :double :byte :short :char or :boolean. The resulting vector complies with the interface of vectors in general, but stores the values unboxed internally. Optionally takes one or more elements to populate the vector.
user=> (conj (vector-of :int) 1 2 3)
[1 2 3] ; <-- note, these are unboxed internally
user=> (vector-of :int 1 2 3)
[1 2 3] ; same here
user=> (type (conj (vector-of :int) 1 2 3))
clojure.core.Vec