Suppose I have the xtensor xexpression waffle
.
xt::xtensor_fixed<double, xt::xshape<1, 4>, xt::layout_type::column_major> open = {{1., 3., 2., 5.}};
xt::xtensor_fixed<double, xt::xshape<1, 4>, xt::layout_type::column_major> close = { {5., 1., 6., 2.} };
auto waffle = xt::equal(open, close);
Considering the type of waffle
is: xt::detail::xfunction_type_t<xt::detail::not_equal_to, xt::xtensor_fixed<double, xt::xshape<1U, 366U>, xt::layout_type::column_major> &, xt::xtensor_fixed<double, xt::xshape<1U, 366U>, xt::layout_type::column_major> &>
I want to pass waffle
into a class constructor:
class WaffleWrapper {
public:
??? waffle;
WaffleWrapper(??? wafflein) {
??? waffle = wafflein;
}
};
What would I use instead of ???
so that I can pass waffle
into it?
e.g.
auto waffle = xt::equal(open, close);
WaffleWrapper example(waffle);
Like I commented, as a rule-of-thumb your class should own its data. You should thus create a data-container, which will force the evaluation of the xfunction
. Thereafter you run no risk on pointing to data that may have gone out-of-scope.
If you are worried about loosing the ability to use the fixedness of your array you could consider templating the class:
#include <xtensor/xarray.hpp>
#include <xtensor/xfixed.hpp>
#include <xtensor/xview.hpp>
#include <xtensor/xio.hpp>
template<class T>
class WaffleWrapper {
public:
T waffle;
WaffleWrapper(const T& wafflein) {
waffle = wafflein;
}
};
int main()
{
using fixed_double = xt::xtensor_fixed<double, xt::xshape<1, 4>, xt::layout_type::column_major>;
using fixed_int = xt::xtensor_fixed<int, xt::xshape<1, 4>, xt::layout_type::column_major>;
fixed_double open = {{1., 3., 2., 5.}};
fixed_double close = {{5., 1., 6., 2.}};
auto waffle = xt::equal(open, close);
WaffleWrapper<fixed_int> example(waffle);
return 0;
}
Note that I abbreviated your typenames for readability.