12-numcxx-sharedptr.cxx

Working with arrays, numcxx style with shared pointers

#include <cstdio>
#include <vector>
#include <memory>
#include <numcxx/numcxx.hxx>

// initialize vector x with some data
void initialize(numcxx::DArray1 &X)
{
  const int n=X.size();
  for (int i=0;i<n;i++) X(i)= 1.0/(double)(1+n-i);
}

// calculate the sum of the elements of x
double sum_elements(numcxx::DArray1 & X)
{
  double sum=0;
  for (int i=0;i<X.size();i++)sum+=X(i);
  return sum;
}

int main()
{
  const int n=1.0e7;
  // call constructor and wrap pointer into smart pointer
  auto pX=numcxx::TArray1<double>::create(n);
  initialize(*pX);  // dereference pointer to obtain reference
  double s=sum_elements(*pX); // dereference pointer to obtain reference
  printf("sum=%e\n",s);
  // smartpointer calls destructor if reference count
  // reaches zero
}