Assert variable types in numba

To assert that a variable is of any specific type, e.g., float32[:], one may apply this trick that makes use of numba signature:

import numba as nb


# Define an auxiliary function that admits only the type you
# want to assert, e.g. float32[:]
assert_f32_1d = nb.njit(nb.none(nb.float32[:]))(lambda x: None)

def function_to_debug_type(x, y, z):
    ...
    some_variable = ...
    ...
    # If `some_variable` is not of type float32[:], numba will
    # point it out.
    assert_f32_1d(some_variable)