Re: [Boost-users] Difficulty using promises and futures

Subject: Re: [Boost-users] Difficulty using promises and futures
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-04-11 18:03:24

Le 11/04/13 00:15, Michael Powell a écrit :
> Hello,
>
> I would like to use promises and futures in our embedded app.
>
> We're targeting ArchLinux ARM. I believe we can build against a GCC 
> 4.7.2 toolchain which has either C++0x or possibly even C++11 
> (somewhat) support.
>
> I am trying to setup a couple of simple issues to make it even 
> compile, but am having trouble.
>
>         boost::packaged_task<vector<int> > 
> int_vect_pt_(simple_vector_getter);
>         boost::unique_future<vector<int> > int_vect_f_ = 
> int_vect_pt_.get_future();
>         boost::thread task(boost::move(int_vect_pt_));
>
>         boost::packaged_task<int> int_pt_(simple_getter);
>         boost::unique_future<int> int_f_ = int_pt_.get_future();
>         boost::thread task(boost::move(int_pt_));
>
> Error(s):
>
> Description    Resource    Path    Location    Type
> 'boost::move' is ambiguous '
> Candidates are:
> boost::type move(boost::packaged_task<int> &)
> '    optics.cpp    /detector/devices    line 156    Semantic Error
>
> Description    Resource    Path    Location    Type
> 'boost::move' is ambiguous '
> Candidates are:
> boost::type 
> move(boost::packaged_task<std::vector<int,std::allocator<int>>> &)
> '    optics.cpp    /detector/devices    line 152    Semantic Error
>
> Can anyone help or otherwise advise? I've even got a "crude" future 
> implementation in C# .NETCF for pity's sake... Anyway, if necessary, 
> what did we do before promises/futures? ;-)
>
>
Hi,

some question:
* which are the ambiguities the compiler finds? I see only one prototype 
for each line.
* which vector are you using std::
* are you compiling with -std=c++0x or -std=c++11?
* what version of Boost.Thread are you using? are you defining 
BOOST_THREAD_VERSION? I suggest you to define it to 4 either at the 
command line/build system or on your source file.

Please could you provide a complete example with the command line you 
are using?

Best,
Vicente