Futures

[DethRaid]

Please add futures and promises for easy returning of data from tasks.

Suggested interface:

template<typename ValType>
class future {
public:
    void on_success(std::function<void(ValType)>);
    void on_failure(std::function<void(ErrorType)>);
    bool is_ready();
    void wait_until_ready();
    ValType&& get_value();
};

[DethRaid]

Oh I'd probably be cool if the on_success or on_failure methods could return another future, so you'd have some way of chaining futures together