Asynchronous tasks outlive main thread

[dpaulat]

supercell-wx/wxdata/include/scwx/util/threads.hpp

Lines 8 to 13 in a474608

	template<class F>
	void async(F&& f)
	{
	auto future = std::make_shared<std::future<void>>();
	*future = std::async(std::launch::async, [future, f]() { f(); });
	}

Because futures are not tracked, if the application exits while an asynchronous operation is still running, undefined behavior can occur within those operations.

A mechanism needs to be created to track these futures and wait for asynchronous tasks to complete.

[dpaulat]

Resolved by bb7793d