Pointers and stuff

ptr_crap.cc

#include <iostream>
#include <memory>
#include <cstdlib>
#include <vector>

void incr(float *arr) {
  arr[5] += 1;
  arr[7] += 1;
}

int main() {
  float *xs = (float*) malloc(sizeof(float) * 10);
  std::shared_ptr<float>(xs, free);

  xs[0] = 5;
  xs[9] = 15;

  std::cout << xs[0] * xs[9] << '\n';

  //auto ys = std::make_shared<float[10]>(new float[10]);
  std::shared_ptr<float[]> ys(new float[10]);

  ys[5] = 5;
  ys[7] = 5;

  std::cout << ys[5] * ys[7] << '\n';

  incr(ys.get());

  std::cout << ys[5] * ys[7] << '\n';

  std::vector<float> zs(10, 0);

  zs[5] = 6;
  zs[7] = 6;

  std::cout << zs[5] * zs[7] << '\n';

  incr(zs.data());

  std::cout << zs[5] * zs[7] << '\n';
}