在 OS X 10.8.5 上使用 Xcode 5.0 和 Qt 5.1.1 构建问题

Build problems with Xcode 5.0 and Qt 5.1.1 on OS X 10.8.5

本文关键字:问题 Qt Xcode 构建 OS      更新时间:2023-10-16

我正在构建的代码,可以在OS X 10.8.5上使用Xcode 4.x,Qt 5.0.1构建良好,但我刚刚升级了Xcode和Qt,在拉入Qt标头时我无法再构建任何东西。

问题是QtSharedPointer 类使用 std::forward,但据我所知,OS X 10.8.5/Xcode 5.0 仍然不支持 std::forward。它没有在随附的标准库中的任何地方定义,因此,当我尝试构建时,出现此错误:

In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtWidgets.framework/Headers/QAction:1:                                                          
In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtWidgets.framework/Headers/qaction.h:47:                                                       
In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtWidgets.framework/Headers/qwidget.h:49:                                                       
In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtGui.framework/Headers/qpalette.h:47:                                                          
In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtGui.framework/Headers/qbrush.h:53:                                                            
In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtGui.framework/Headers/qpixmap.h:49:                                                           
In file included from .../Qt5.1.1/5.1.1/clang_64/lib/QtCore.framework/Headers/qsharedpointer.h:50:                                                   
.../Qt5.1.1/5.1.1/clang_64/lib/QtCore.framework/Headers/qsharedpointer_impl.h:411:36: error: no template named 'forward' in namespace 'std'; did you mean 'boost::forward'?
        new (result.data()) T(std::forward<Args>(arguments)...);                                                                                     
                            ~~~~~^~~~~~~                                                                                                             
                            boost::forward                                                                                                           
/usr/local/include/boost/move/utility.hpp:176:21: note: 'boost::forward' declared here                                                               
        inline T&& forward(U&& t                                                                                                                     
                    ^                                                                                                                                

我确实注意到QtSharedPointer标题顶部的这些行:

#if defined(Q_COMPILER_RVALUE_REFS) && defined(Q_COMPILER_VARIADIC_TEMPLATES)                                                                            
#  include <utility>           // for std::forward                                                                                                       
#endif

但在下面(第 411 行),它只使用 std::forward,而不检查是否定义了这些宏

    // now initialize the data
    new (result.data()) T(std::forward<Args>(arguments)...);

这些宏实际上是未定义的,所以,我最初强制包含实用程序,但由于我后来发现 std::forward 不在那里,它没有帮助。

这似乎是一个Qt错误,我打算在那里提交它,但是有人想出解决方法吗?

实际上,我意识到使用 std::forward 的整个方法都由另一个检查Q_COMPILER_RVALUE_REFS的 ifdef 保护。我只是简单地编辑了QtCore.framework/Versions/5/Headers/qcompilerdetection.h,并手动未定义Q_COMPILER_RVALUE_REFS,这让我开始构建。