enqueue: capture by universal reference

[daniel-j-h]

Is there a reason the enqueue function doesn't capture the type-deduced function as universal reference? E.g.:

template<typename Function>
auto enqueue(Function&& f) -> std::future<decltype(std::forward<F>(f)())>;

This would allows us to std::forward(f) later on, preserving the rvalue/lvalue type.

This should handle situations nicely where we enqueue

• rvalues (e.g. anonymous lambdas)
• lvalues (e.g. named functors)

[progschj]

Sorry for the lat answer, I was stuck in the military for a few weeks...
The only reason is my still limited knowledge of C++11 ;). I incorporated this in the develop branch.