我在Eclipse论坛上找到了这篇文章，只需要按照这些步骤，它就适合我了。我在Windows上使用Cygwin设置的Eclipse Indigo 20110615-0604。

Make a new C++ project Default options for everything Once created, right-click the project and go to "Properties" C/C++ Build -> Settings -> Tool Settings -> GCC C++ Compiler -> Miscellaneous -> Other Flags. Put -std=c++0x (or for newer compiler version -std=c++11 at the end . ... instead of GCC C++ Compiler I have also Cygwin compiler C/C++ General -> Paths and Symbols -> Symbols -> GNU C++. Click "Add..." and paste __GXX_EXPERIMENTAL_CXX0X__ (ensure to append and prepend two underscores) into "Name" and leave "Value" blank. Hit Apply, do whatever it asks you to do, then hit OK.

现在在Eclipse FAQ/ c++ 11 Features中也有关于这方面的描述。

Eclipse设置

右键单击项目，选择“属性” C/ c++ Build -> Settings -> Tool Settings -> GCC c++ Compiler -> Miscellaneous -> Other Flags。将-lm放在其他标志文本框的末尾，然后确定。

我在使用Eclipse c++ 2019-03进行C和c++混合项目时遇到了类似的问题，该项目使用std::optional和std::swap。对我有用的是这个。

在项目中 属性->C/ c++构建->设置->工具设置->交叉g++编译器，从Miscellaneous中删除-std= gn++ 17，并将其放在Dialect->Other Dialect Flags中。

我在Eclipse论坛上找到了这篇文章，只需要按照这些步骤，它就适合我了。我在Windows上使用Cygwin设置的Eclipse Indigo 20110615-0604。

Make a new C++ project Default options for everything Once created, right-click the project and go to "Properties" C/C++ Build -> Settings -> Tool Settings -> GCC C++ Compiler -> Miscellaneous -> Other Flags. Put -std=c++0x (or for newer compiler version -std=c++11 at the end . ... instead of GCC C++ Compiler I have also Cygwin compiler C/C++ General -> Paths and Symbols -> Symbols -> GNU C++. Click "Add..." and paste __GXX_EXPERIMENTAL_CXX0X__ (ensure to append and prepend two underscores) into "Name" and leave "Value" blank. Hit Apply, do whatever it asks you to do, then hit OK.

现在在Eclipse FAQ/ c++ 11 Features中也有关于这方面的描述。

Eclipse设置

对于Eclipse CDT Kepler，我摆脱std::线程未解析符号的工作是:

进入“首选项->C/ c++ ->构建->设置” 选择Discovery选项卡 选择CDT GCC内置编译器设置[共享] 在“Command to get compiler specs:”字段中添加-std=c++11，例如:

${COMMAND} -E -P -v -dD -std=c++11 ${输入}

好的，然后重建项目的索引。

添加-std=c++11到项目属性/ c / c++构建->设置->工具设置->GCC c++编译器->杂项->其他 对于开普勒来说，旗帜还不够，但对于较老的版本，如太阳神，它已经足够了。

我还不能评论，所以我写了我自己的答案:

它与__GXX_EXPERIMENTAL_CXX0X__相关，对Eclipse Juno和CDT 8.x有效。

这个答案的一些部分已经在其他答案中涵盖了，但我希望它是连贯的。

为了能够使用stdc++11构建，必须为编译器添加特定的标志。您可以通过项目属性来实现这一点。修改项目属性RMB和项目属性或ALT + ENTER。然后C/ c++构建->设置->工具设置-> GCC c++编译器-> Miscellaneous ->其他标志。将-std=c++11放在行末，对于GCC来说，它看起来像这样:-c -fmessage-length=0 -std=c++11。通过添加-stdc++11标志，编译器(GCC)将自己声明__GXX_EXPERIMENTAL_CXX0X__。

此时，您可以使用c++ 11的所有优点来构建项目。

The problem is that Eclipse has it's own parser to check for errors - that's why you're still getting all the nasty errors in Eclipse editor, while at the same time you can build and run project without any. There is a way to solve this problem by explicitly declaring __GXX_EXPERIMENTAL_CXX0X__ flag for the project, one can do that (just like Carsten Greiner said): C/C++ General -> Paths and Symbols -> Symbols -> GNU C++. Click "Add..." and past __GXX_EXPERIMENTAL_CXX0X__ (ensure to append and prepend two underscores) into "Name" and leave "Value" blank. And now is the extra part I wanted to cover in comment to the first answer, go to: C/C++ General -> Preprocessor Include Path Macros etc. -> Providers, and Select CDT Managed Build Setting Entries then click APPLY and go back to Entries tab, under GNU C++ there should be now CDT Managed Build Setting Entries check if inside there is defined __GXX_EXPERIMENTAL_CXX0X__ if it is -> APPLY and rebuild index you should be fine at this point.