def _make_inplace_ufunc_op_usecase(ufunc_op):
    """Generates a function to be compiled that performs an inplace operation

    ufunc_op can be a string like '+=' or a function like operator.iadd
    """
    if isinstance(ufunc_op, str):
        ldict = {}
        exec("def fn(x,y):\n    x{0}y".format(ufunc_op), globals(), ldict)
        fn = ldict["fn"]
        fn.__name__ = "usecase_{0}".format(hash(ufunc_op))
    else:
        def inplace_op(x, y):
            ufunc_op(x, y)
        fn = inplace_op
    return fn
Generates a function to be compiled that performs an inplace operation

    ufunc_op can be a string like '+=' or a function like operator.iadd
    
numba/tests/test_ufuncs.py