I kind of agree with korczurekk SF:Time could be replaced with std::chrono
But if we go further we can also remove :
sf::Threads => std::thread
sf::ThreadLocal => no need if sf::Threads become a std::thread ? (not sure what it does)
sf::sleep => std::this_thread::sleep_for
sf::Clock => std::chrono::high_resolution_clock
sf::FileInputStream => std::ifstream (literally the same)
sf::InputStream => std::istream (literally the same)
sf::Lock => std::lock_guard (literally the same ... again)
sf::MemoryInputStream => if sf::InputStream become a std::istream we won't need this anymore
sf::Mutex => std::mutex
...
Well a good part of System could be removed in favor of a Standard implementation
Also when will the SFML 3 project/branch be started?