It appears that you want to pass two input vectors to thrust::transform
and then do an in-place transform (i.e. no output vector is specified).
There is no such incarnation of thrust::transform
Since you have passed:
thrust::transform(vector_first, vector_last, vector_first, operator);
The closest matching prototype is a version of transform that takes one input vector and creates one output vector. In that case, you would need to pass a unary op that takes the input vector type (hashElem
) only as an argument, and returns a type appropriate for the output vector, which is int
in this case, i.e. as you have written it (not as your intent). Your operator()
does not do that, and it cannot be called with the arguments that thrust is expecting to pass to it.
As I see it, you have a couple options:
You could switch to the version of transform that takes two input vectors and produces one output vector, and create a binary op as functor.
You could zip together your two input vectors, and do an in-place transform if that is what you want. Your functor would then be a unary op, but it would take as argument whatever tuple was created from dereferencing the input vector, and it would have to return or modify the same kind of tuple.
As an aside, your method of creating device pointers directly from host arrays looks broken to me. You may wish to review the thrust quick start guide.