Remove possibility to change CMAKE_CXX_STANDARD

[SunBlack]

#2690 added

pcl/CMakeLists.txt

Line 11 in a2bedc9

set(CMAKE_CXX_STANDARD 14 CACHE STRING "The target C++ standard. PCL requires C++14 or higher.")

It is nice that we can switch C++14 and C++17, but we only support C++14, because we don't touch 3rd-Party code and with C++17 you get following error message:

/media/sf_pcl/surface/src/3rdparty/opennurbs/opennurbs_evaluate_nurbs.cpp:512:3: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  register double alpha0;
  ^~~~~~~~~
/media/sf_pcl/surface/src/3rdparty/opennurbs/opennurbs_evaluate_nurbs.cpp:513:3: error: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
  register double alpha1;
...

So we remove the option to allow the user to change the standard, as we know, only C++14 works and nothing other.

[taketwo]

Let's just do s/register //g.

[SunBlack]

Or can we update OpenNURBS? There register is already removed:

https://github.com/mcneel/opennurbs/blob/b844466e88fcf5a42c9d6d526abb3dcc44f939b5/opennurbs_evaluate_nurbs.cpp#L519-L523

[SergioRAgostinho]

Right now, it doesn't bother anyone. Since the our goal of allowing the user to select the standard >= C++14 has not changed, I would leave it untouched. Once we finish the correcting the changes that will allow PCL to be compiled with C++17, this will be one less thing to do.

[stale]

Marking this as stale due to 30 days of inactivity. It will be closed in 7 days if no further activity occurs.

[kunaltyagi]

What about updating the 3rd party libs?

[SunBlack]

I don't know about the license of 3rd party libs, if we are allowed to do so. In general I would prefer to integrate them via CMake and remove the code from our repo - but most of the 3rd party libs are not really CMake conform :-(

[SergioRAgostinho]

1. OpenNurbs: https://github.com/mcneel/opennurbs the project is still active, the license is something akin to MIT. When the code was added into our source tree it referred to the same organization. It would need some patching plus interest from the mother organization to modernize the build process.

2. Poisson Reconstruction:

• Original project page: http://www.cs.jhu.edu/~misha/Code/PoissonRecon/Version12.00/
• GitHub: https://github.com/mkazhdan/PoissonRecon/
• CMake enabled repo tailored for MATLAB: https://github.com/daeyun/poisson-surface-reconstruction
• Original Commit: 3b20c6b

Then again, why care about surface reconstruction as a point cloud focused library. Dense meshes are for newbies. :D (sarcasm)

[stale]

Marking this as stale due to 30 days of inactivity. It will be closed in 7 days if no further activity occurs.