C++ Basic profiling timer class

timer.h

class Timer
{
public:
  Timer(std::string label_) : start{std::chrono::high_resolution_clock::now()}, label{label_} {};

  ~Timer() { print(); }

  void print() {
    finish = std::chrono::high_resolution_clock::now();
    auto elapsed_ms = std::chrono::duration_cast<std::chrono::duration<double>>(finish - start).count() * 1000;
    std::cout << label << "=" << elapsed_ms << "ms\n";
  }

private:
  std::chrono::time_point<std::chrono::high_resolution_clock> start, finish;
  std::string label;
};

line 4: best practice is not to copy std::string label_ and rather take it by ref like this: const std::string& label_

line 4: best practice is not to copy std::string label_ and rather take it by ref like this: const std::string& label_

Thanks. Yes, that's fair comment. This is actually a very old version of that code.

More up to date version here:
https://github.com/oschonrock/toolbelt/blob/master/os/bch.hpp

Which uses "pass by value and then move" - because we want our own copy of the label - but avoids the double copy which, as you point out, the above code is doing.