Latest Qt requires -std=c++14

[parkerlreed]

Description

Compile fails with Qt enabled with this error. After searching, it appears std::exchange was introduced in c++14 although RetroArch seems to use c++11 by default.

/usr/include/qt/QtCore/qsharedpointer_impl.h: In function ‘std::shared_ptr<_Tp> qobject_pointer_cast(std::shared_ptr<_Tp>&&)’:
/usr/include/qt/QtCore/qsharedpointer_impl.h:1019:40: error: ‘exchange’ is not a member of ‘std’
 1019 |         return std::shared_ptr<X>(std::exchange(src, nullptr), castResult);
      |                                        ^~~~~~~~
CXX ui/drivers/qt/qt_options.cpp
In file included from /usr/include/qt/QtCore/qsharedpointer.h:48,
                 from /usr/include/qt/QtCore/qdebug.h:54,
                 from /usr/include/qt/QtCore/qcborcommon.h:45,
                 from /usr/include/qt/QtCore/qcborvalue.h:45,
                 from /usr/include/qt/QtCore/qcborarray.h:43,
                 from /usr/include/qt/QtCore/QtCore:38,
                 from /usr/include/qt/QtWidgets/QtWidgetsDepends:3,
                 from /usr/include/qt/QtWidgets/QtWidgets:3,
                 from ui/drivers/ui_qt.cpp:19:
/usr/include/qt/QtCore/qsharedpointer_impl.h: In function ‘std::shared_ptr<_Tp> qobject_pointer_cast(std::shared_ptr<_Tp>&&)’:
/usr/include/qt/QtCore/qsharedpointer_impl.h:1019:40: error: ‘exchange’ is not a member of ‘std’
 1019 |         return std::shared_ptr<X>(std::exchange(src, nullptr), castResult);
      |                                        ^~~~~~~~
In file included from /usr/include/qt/QtCore/qsharedpointer.h:48,
                 from /usr/include/qt/QtGui/qpixmap.h:48,
                 from /usr/include/qt/QtGui/qbrush.h:52,
                 from /usr/include/qt/QtGui/qpalette.h:46,
                 from /usr/include/qt/QtWidgets/qwidget.h:48,
                 from /usr/include/qt/QtWidgets/qdialog.h:44,
                 from /usr/include/qt/QtWidgets/qprogressdialog.h:45,
                 from /usr/include/qt/QtWidgets/QProgressDialog:1,
                 from ui/drivers/qt/qt_downloads.cpp:3:

Expected behavior

Qt bits compile

Actual behavior

Qt bits don't compile and abort entire build

Steps to reproduce the bug

1. Compile RetroArch on defaults
2. Observe error

Version/Commit

You can find this information under Information/System Information

• RetroArch: master 3bc06b0

Environment information

• OS: Arch Linux
• Compiler: gcc 11.1.0-1

qt5-base 5.15.2+kde+r209-1

[parkerlreed]

I've attempted to use CXXFLAGS+=" -std=c++14" before the configure but it still seems to force c++11 (as noted in the configure output)

[parkerlreed]

qt5-base updated and the compile now works.

qt5-base-5.15.2+kde+r210-1

[parkerlreed]

archlinux/svntogit-packages@0060f39#diff-3e341d2d9c67be01819b25b25d5e53ea3cdf3a38d28846cda85a195eb9b7203a