Cross platform Sleep function for C++

Question

Is it possible with macros make cross platform Sleep code? For example

#ifdef LINUX
#include <header_for_linux_sleep_function.h>
#endif
#ifdef WINDOWS
#include <header_for_windows_sleep_function.h>
#endif
...
Sleep(miliseconds);
...

Answer 1

Yup. But this only works in C++11 and later.

#include <chrono>
#include <thread>
...
std::this_thread::sleep_for(std::chrono::milliseconds(ms));

where ms is the amount of time you want to sleep in milliseconds.

You can also replace milliseconds with nanoseconds, microseconds, seconds, minutes, or hours. (These are specializations of the type std::chrono::duration.)

Update: In C++14, if you're sleeping for a set amount of time, for instance 100 milliseconds, std::chrono::milliseconds(100) can be written as 100ms. This is due to user defined literals, which were introduced in C++11. In C++14 the chrono library has been extended to include the following user defined literals:

• std::literals::chrono_literals::operator""h
• std::literals::chrono_literals::operator""min
• std::literals::chrono_literals::operator""s
• std::literals::chrono_literals::operator""ms
• std::literals::chrono_literals::operator""us
• std::literals::chrono_literals::operator""ns

Effectively this means that you can write something like this.

#include <chrono>
#include <thread>
using namespace std::literals::chrono_literals;

std::this_thread::sleep_for(100ms);

Note that, while using namespace std::literals::chrono_literals provides the least amount of namespace pollution, these operators are also available when using namespace std::literals, or using namespace std::chrono.