Moving to C++14

[SergioRAgostinho]

Just aggregating the points we've discussed at the hackfest.

• enable C++14flags
• remove dependency on boost-thread and move to STL
• remove dependency on boost-iostream (? @nizar-sallem will need to confirm this)

[awilliamson]

👍+1 for removing boost dependency.

[nznobody]

+1! Would make portability easier again (I know boost is super portable too...)

[giacomodabisias]

+1!

[VictorLamoine]

I think we should also replace boost smart pointers with std ones.
Most C++ compilers now have C++11 support right?

[taketwo]

Easier to say than to do. It's true that most compilers support C++11, it will even become the default in GCC soon. Nevertheless, not everyone wants (or can) compile their code in C++11 mode. And if we switch to STL smart pointers, that will force all code that uses PCL to be compiled in C++11 mode. For a concrete example of how this can lead to problems, refer to this thread.

[giacomodabisias]

Just set a flag in the cmake file so that you can choose if you want to use std or boost shared pointers.
Even something like this would be enough

#pragma once
#ifdef WITH_STD_SHARED_PTR
    #include <memory>
    using std::shared_ptr;
    using std::make_shared;
    using std::static_pointer_cast;
    using std::dynamic_pointer_cast;
#else
    #include <boost/shared_ptr.hpp>
    #include <boost/make_shared.hpp>
    #include <boost/pointer_cast.hpp>
    using boost::shared_ptr;
    using boost::make_shared;
    using boost::static_pointer_cast;
    using boost::dynamic_pointer_cast;
#endif

[taketwo]

This is indeed possible. But do we actually gain anything?

[giacomodabisias]

I already had issues with that. Every other library which wants to build on top of PCL or wants to use PCL inside has to use boost shared pointers even if it wants to use std shared pointers inside. Also it is an unnecessary dependency which you will always have. I think that sticking to the standard is always the best way to remain portable and open, so I would say its not mandatory but strongly recommended.

[taketwo]

But both std and boost pointers can co-exist. It's true that the PCL-related objects (i.e. point clouds, octrees, etc.) have to be managed by boost pointers, but everything else in your program/library is free to adhere to the standard.

Even if we get rid of boost smart pointers completely, we will still need other modules of Boost, so this dependency will never be dropped.

I also prefer standard solutions and have been using C++11 where ever possible for more than five years now. But my feeling is that if we can not make a wholesale jump to C++11 just yet, it does not make much sense to implement partial conversions and maintain them.

[giacomodabisias]

Yeah they can co-exist, thats true, but since the standard moved I think PCL should catch up. Else you are forcing users to use boost also in their libraries if they want to use pcl

[taketwo]

As I said, even without it's smart pointers, Boost is a cornerstone dependency of PCL. We rely on many other Boost modules that are not in the standard, so the PCL users are doomed to use Boost anyway.

[feliwir]

couldn't be there a version without boost usage? Something stripped down. It's pretty much the largest dependency of PCL by far