Casting an input value using block() function


My question is related to the work function using block() as provided in
GRExtras. I have a block that input a gr_complex value and output a
gr_complex value. I’m trying to cast the input and output, in order to
them in my work function, what I have is:

int work(
const InputItems &input_items,
const OutputItems &output_items

  std::complex<float> * in = input_items[0].cast<std::complex<float>

std::complex * out =

 //Processing here

} //End of work function

I can cast the output without problem, but I cannot do it for the input.
got the following error:

/home/project/grextras/include/gnuradio/block.h: In member function T
gnuradio::Buffer::cast() const [with T = std::complex,
PtrType = const void
from here
/home/project/grextras/include/gnuradio/block.h:43:47: error:
reinterpret_cast from type const void* to type std::complex*
casts away qualifiers

So, I checked into the block.h I have the following:

typedef std::vector<Buffer<const void *> > InputItems;
typedef std::vector<Buffer<void *> > OutputItems;

Does it mean that I cannot cast my input_items in my work function?
If the answer is no, how can I use the input_items in my work function?,
because I have to receive a stream of values.

Thanks for your comments,




In order to add more information, I found some information here:

As I understand, the issue is with this line in block. h

typedef std::vector<Buffer<const void *> > InputItems;

Because it is casting using const, rather than:

typedef std::vector<Buffer<void *> > OutputItems;

I’m stuck in this point, because I’m not sure how to use the input_items
my work function, if I’m not able to cast it.



On Mon, Nov 5, 2012 at 10:42 AM, Jose T. Diaz
<[email protected]

Thanks Bastian,

This fix the issue,