Here's some code that I found:

```cpp
std::cout << std::chrono::system_clock::now().time_since_epoch().count() << std::endl;

```

This prints `1662563612364838407` for me; so it looks like this prints the number of nanoseconds since the UNIX epoch (1970-01-01).

But is this precision guaranteed? I didn't find any indication at <https://en.cppreference.com/w/cpp/chrono/system_clock> that this value will always be in nanoseconds. Is it possible that this will return e.g. microseconds with another compiler, operating system or hardware?