// In header: <hpx/lcos/wait_all.hpp> template<typename... T> void wait_all(T &&... futures);
The function wait_all is a operator allowing to join on the result of all given futures. It AND-composes all future objects given and returns the same list of futures after they finished executing.
The function wait_all returns after all futures have become ready. All input futures are still valid after wait_all returns.