title: How to concatenate two numpy ndarrays without using concatenate
body: <p>I am writing code which utilizes Numba to JIT compile my python code.
  The function takes in two arrays of same length as input, randomly selects a slicing point and returns a tuple with two Frankenstein array formed by parts of the two input strings.
  Numba however does not yet support the numpy.concatenate function (don't know if it ever will). As I am unwilling to drop Numpy, does anyone know a performant solution for concatenating two Numpy arrays without the concatenate function?</p>
  
  <pre><code>def randomSlice(str1, str2):
      lenstr = len(str1)
      rnd = np.random.randint(1, lenstr)
      return (np.concatenate((str1[:rnd], str2[rnd:])), np.concatenate((str2[:rnd], str1[rnd:])))
  </code></pre>