[LyX/master] Add move constructor and move assignment operator for FileName class

[Yuriy Skalko]

> 
> I've tried to reproduce on Linux with Clang and libc++ but cannot.
> However, one thing that I do not understand is that in the output from
> ldd, both libstdc++.so.6 and libc++.so.1 show up. See attached. Is this
> expected?
> 
> Scott
> 
>         linux-vdso.so.1 (0x00007ffd059e5000)
>         libmythes-1.2.so.0 => /lib/x86_64-linux-gnu/libmythes-1.2.so.0 
> (0x00007f990dad1000)
>         libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x00007f990d993000)
>         libQt5X11Extras.so.5 => /lib/x86_64-linux-gnu/libQt5X11Extras.so.5 
> (0x00007f990d98c000)
>         libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f990d962000)
>         libenchant-2.so.2 => /lib/x86_64-linux-gnu/libenchant-2.so.2 
> (0x00007f990d954000)
>         libmagic.so.1 => /lib/x86_64-linux-gnu/libmagic.so.1 
> (0x00007f990d92c000)
>         libQt5Concurrent.so.5 => /lib/x86_64-linux-gnu/libQt5Concurrent.so.5 
> (0x00007f990d921000)
>         libQt5Svg.so.5 => /lib/x86_64-linux-gnu/libQt5Svg.so.5 
> (0x00007f990d8c5000)
>         libQt5Widgets.so.5 => /lib/x86_64-linux-gnu/libQt5Widgets.so.5 
> (0x00007f990d229000)
>         libQt5Gui.so.5 => /lib/x86_64-linux-gnu/libQt5Gui.so.5 
> (0x00007f990cb71000)
>         libQt5Core.so.5 => /lib/x86_64-linux-gnu/libQt5Core.so.5 
> (0x00007f990c633000)
>         libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f990c616000)
>         libc++.so.1 => /lib/x86_64-linux-gnu/libc++.so.1 (0x00007f990c54e000)
>         libc++abi.so.1 => /lib/x86_64-linux-gnu/libc++abi.so.1 
> (0x00007f990c516000)
>         libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f990c3c7000)
>         libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 
> (0x00007f990c3ac000)
>         libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f990c1c2000)
>         /lib64/ld-linux-x86-64.so.2 (0x00007f990dafb000)
>         libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 
> (0x00007f990bfe1000)
>         libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f990bfd9000)
>         libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x00007f990bfd3000)
>         libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6 
> (0x00007f990bfcb000)
>         libgmodule-2.0.so.0 => /lib/x86_64-linux-gnu/libgmodule-2.0.so.0 
> (0x00007f990bfc5000)
>         libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 
> (0x00007f990be93000)
>         liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f990be6a000)
>         libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 
> (0x00007f990be55000)
>         libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 
> (0x00007f990be33000)
>         libGL.so.1 => /lib/x86_64-linux-gnu/libGL.so.1 (0x00007f990bdab000)
>         libpng16.so.16 => /lib/x86_64-linux-gnu/libpng16.so.16 
> (0x00007f990bd72000)
>         libharfbuzz.so.0 => /lib/x86_64-linux-gnu/libharfbuzz.so.0 
> (0x00007f990bc91000)
>         libmd4c.so.0 => /lib/x86_64-linux-gnu/libmd4c.so.0 (0x00007f990bc7d000)
>         libdouble-conversion.so.3 => 
> /lib/x86_64-linux-gnu/libdouble-conversion.so.3 (0x00007f990bc65000)
>         libicui18n.so.67 => /lib/x86_64-linux-gnu/libicui18n.so.67 
> (0x00007f990b953000)
>         libicuuc.so.67 => /lib/x86_64-linux-gnu/libicuuc.so.67 
> (0x00007f990b767000)
>         libpcre2-16.so.0 => /lib/x86_64-linux-gnu/libpcre2-16.so.0 
> (0x00007f990b6e4000)
>         libzstd.so.1 => /lib/x86_64-linux-gnu/libzstd.so.1 (0x00007f990b614000)
>         librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f990b607000)
>         libatomic.so.1 => /lib/x86_64-linux-gnu/libatomic.so.1 
> (0x00007f990b5fd000)
>         libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f990b5e3000)
>         libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f990b570000)
>         libGLdispatch.so.0 => /lib/x86_64-linux-gnu/libGLdispatch.so.0 
> (0x00007f990b4b8000)
>         libGLX.so.0 => /lib/x86_64-linux-gnu/libGLX.so.0 (0x00007f990b482000)
>         libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6 
> (0x00007f990b3bf000)
>         libgraphite2.so.3 => /lib/x86_64-linux-gnu/libgraphite2.so.3 
> (0x00007f990b392000)
>         libicudata.so.67 => /lib/x86_64-linux-gnu/libicudata.so.67 
> (0x00007f9909879000)
>         libbrotlidec.so.1 => /lib/x86_64-linux-gnu/libbrotlidec.so.1 
> (0x00007f990986b000)
>         libbrotlicommon.so.1 => /lib/x86_64-linux-gnu/libbrotlicommon.so.1 
> (0x00007f9909846000)
> 

Yes, this is expected, since system libQt5*.so are dependent on 
libstdc++ (assuming you haven't rebuild Qt with libc++). ldd displays 
all required libraries, not only the ones that directly used by the 
application.

So, seems that the issue with move constuctor patch is shown up only on 
macOS. Now I'm not sure how to debug it, since I have no Mac.


Yuriy