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Comment by mhogomchungu | Hacker News Reader

sometimes,declaring lambdas with auto is not not sufficient as i discovered in my "tasks"[1] project. An example place where auto breaks is here[2].

[1] https://github.com/mhogomchungu/tasks

[2] https://github.com/mhogomchungu/tasks/blob/a1512a1b5e0392a06...

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The problem there is in your Task::run() function. It now looks like this in the commit I just saw:

        template< typename T,typename ... Args >
	future<T>& run( std::function< T( Args ... ) > function,Args ... args )
	{
		return Task::run<T>( std::bind( std::move( function ),std::move( args ) ... ) ) ;
        }

It should look like this for that example to work without the type erasure (haven't tried, there might be typos):

        template< typename Fn,typename ... Args >
	future<std::result_of_t(Fn(Args...))>& run( Fn&&, Args&& ... args )
	{
		return Task::run<std::result_of_t(Fn(Args...))>( std::bind( std::forward<Fn>( function ),std::forward<Args>( args ) ... ) ) ;
        }

This version is also more efficient, since otherwise you are type erasing twice.

Your code failed to compile but this one[1] succeeds. Side effect of your way is that it now makes the project requiring C++14 but i can live with that.

[1] https://github.com/mhogomchungu/tasks/blob/4210a8fad57958fad...

You can change the `std::result_of_t<...>` for `typename std::result_of<...>::type` to make it work in C++11 :)

All my projects are C++14 so it wasnt an issue for me but i liked being c++11 for other people and i am glad there is a way to get it back to c++11. Already committed your suggestion.

Thank you very much.

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