Access Unity Primitive Shape Meshes

Is there a way I can access the cube or any of them without creating a variable and storing the cube mesh in there?

 line.AddComponent<MeshFilter>().mesh = 

Edit: I just learned about this which solves my problem. But, for future reference, is there a way do still do what I was asking before? Set the mesh to a primative without instantiating it with one?

 GameObject line = GameObject.CreatePrimitive(PrimitiveType.Cube);