Add necessary boost headers to pcl/io to build in CUDA mode

[bowang]

Currently all boost headers are disabled in pcl/io/boost.h when building in CUDA mode. However, boost is used in file_io.h and pcd_io.h. This PR adds the boost headers to make sure they can build when CUDA is enabled.

[SergioRAgostinho]

What exactly is the compilation error you're getting by not including these?

[denix56]

1>------ Build started: Project: pcl_io, Configuration: Release x64 ------
1>pcd_io.cpp
1>D:\dev-tools\pcl\io\src\pcd_io.cpp(770): error C2065: 'ssize_t': undeclared identifier
1>D:\dev-tools\pcl\io\src\pcd_io.cpp(770): error C2146: syntax error: missing ';' before identifier 'num_read'
1>D:\dev-tools\pcl\io\src\pcd_io.cpp(770): error C2065: 'num_read': undeclared identifier
1>D:\dev-tools\pcl\io\src\pcd_io.cpp(771): error C2065: 'num_read': undeclared identifier
1>Done building project "pcl_io.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

[bowang]

pcl/io/include/pcl/io/file_io.h(346): error: namespace "boost" has no member "iequals"
pcl/io/include/pcl/io/file_io.h(372): error: namespace "boost" has no member "iequals"
pcl/io/include/pcl/io/pcd_io.h(584): error: name followed by "::" must be a class or namespace name
pcl/io/include/pcl/io/pcd_io.h(592): error: name followed by "::" must be a class or namespace name

[SergioRAgostinho]

So the problem between Boost and CUDA seem to be related to this https://stackoverflow.com/questions/7399688/cuda-with-boost . Nevertheless, recent boost versions started to take into account CUDA and NVCC.

The solution you propose is a workaround which might work only for your particular development environment, but we'll need other users to report problems to fully know. Nevertheless your include lines must be added to pcl/io/boost.h outside the __CUDACC__ ifdef guard to be consistent. Don't forget the QT as well.

[bowang]

Thanks for the feedback, Sergio. I moved the headers into pcl/io/boost.h. Please let me know of any other suggestions.

[SergioRAgostinho]

We can save some if guards by doing the following: the current header file structure is something like this

#ifndef __CUDACC__
    #ifndef Q_MOC_RUN
        [...]
        <the headers you need came from this level>
        [...]
        #if BOOST_VERSION >= 104700
            [...]
        #endif
        [...]
        #if BOOST_VERSION >= 104900
            [...]
        #endif
    #endif /* Q_MOC_RUN */
#endif /* __CUDACC__*/

In order to reduce the number of if guards and account for your changes, you need to interchange Q_MOC_RUN and __CUDACC__ indentation levels, like this

#ifndef Q_MOC_RUN
    #ifndef __CUDACC__
        [...]
        <the headers you need came from this level ... (see below)>
        [...]
        #if BOOST_VERSION >= 104700
            [...]
        #endif
        [...]
        #if BOOST_VERSION >= 104900
            [...]
        #endif
    #else /* __CUDACC__*/
        <(cont.) ... and they are placed at this level>
    #endif /* __CUDACC__*/
#endif /* Q_MOC_RUN */

Please delete also lines 67 and 69. They're useless.

[SergioRAgostinho]

You need to erase the copy of this in line 66.

[bowang]

Fixed

[bowang]

Thanks for the detailed instruction. Just updated accordingly. I also added indentation and comments on #ifndef #endif macros to improve readability.

[SergioRAgostinho]

So... I appreciate the intention 😅 but we have this policy of not changing the indentation of the code, unless your changes actually affect those lines. We do this to make sure that our git blame is not "polluted" with authors which were not responsible for those lines. Therefore I need to ask only change what is really necessary.

One again my apologies.

[bowang]

No problem. Just removed the indentation and keep changes to minimum.

[SergioRAgostinho]

Thanks 👍

Comment to maintainers: squash commits