freeVector function in Auxiliary.h takes input by value but it should take it by reference

[aasivas]

I am copying the function implementation in auxiliary/Auxiliary.h below. This function should take the input by value, otherwise a temporary copy is made, cleared and shrunk, while the original vector is left as is.

template <typename T>
void freeVector(std::vector<T> v) {
  // Give up memory allocated to v.
  // (technically shrink_to_fit does not guarantee to deallocate)
  v.clear();
  v.shrink_to_fit();
}

Here is a small snippet (with slightly modified freeVector) to demonstrate this function does not modify its input

#include <vector>
#include <cstdio>

template <typename T>
void freeVector(std::vector<T> v) {
  // Give up memory allocated to v.
  // (technically shrink_to_fit does not guarantee to deallocate)
  v[0] = 5.;
  printf("v = %g %g %g \n", v[0], v[1], v[2]);
  v.clear();
  v.shrink_to_fit();
}

int main() {
  std::vector<double> a = {1., 2., 3.};
  freeVector(a);
  printf("a = %g %g %g \n", a[0], a[1], a[2]);
  return 0;
}

Fix is as below:

template <typename T>
void freeVector(std::vector<T>& v) {

Let me know if you want to fix this yourself or if you want me to submit an MR. I found this issue after observing some excessive memory usage.

[filikat]

Thank you. I already noticed this and I have it fixed on a separate branch.

[aasivas]

Awesome! Thanks for the reply :) Do you prefer me to close the issue then? Or do you want to close it when you merge your branch instead?

[filikat]

I will close the issue, thanks.

[filikat]

Closed by #2762