[ctypes-users] Dereferencing a slice of pointer (was: Re: Dereferencing a pointer)

[Holger D. <H.D...@gm...>]

On a related note:

I am currently trying to wrap a function which allocates a buffer for
me; something like
,----
| int foo(char **out_buffer, size_t *out_buffer_length);
`----

The data in the buffer can be binary, i.e. it may contain a 0-byte,
which is why we get a length returned as well.

Because of the 0-byte, I cannot use something like 

,----
| out_buffer = c_char_p()
| out_buffer_length = c_int()
| success = the_lib.foo(byref(out_buffer), byref(out_buffer_length))
`----

What I currently have is:
,----
| out_buffer = POINTER(c_char)()
| out_buffer_length = c_int()
| success = the_lib.foo(pointer(out_buffer), byref(out_buffer_length))
| out_buffer = "".join([out_buffer[i] for i in range(out_buffer_length)])
`----
and this works.

Two questions:
a) Could this be done better?

b) Why doesn't the pointer metaclass support slicing?  I.e. this could
   have simplified my last line to
   ,----
   | out_buffer = "".join(out_buffer[:out_buffer_length])
   `----
   I had a quick glance at the code and it is just missing -- is this
   intentional or just not yet done?


Thanks,
        Holger