Eclipse 3.7.1 CDT 1.4.1 GCC 4.6.2
This is an example of a piece of C++11 code:
auto text = std::unique_ptr(new char[len]); The Eclipse editor complains about:
Function 'unique_ptr' could not be resolved The Makefile compilation works fine. How to make Eclipse stop complaining about these sort of errors?
I found this article in the Eclipse forum, just followed those steps and it works for me. I am using Eclipse Indigo 20110615-0604 on Windows with a Cygwin setup.
-std=c++0x (or for newer compiler version -std=c++11 at the end . ... instead of GCC C++ Compiler I have also Cygwin compiler__GXX_EXPERIMENTAL_CXX0X__ (ensure to append and prepend two underscores) into "Name" and leave "Value" blank.There is a description of this in the Eclipse FAQ now as well: Eclipse FAQ/C++11 Features.
First, before creating project, configure Eclipse syntax parser:
Window -> Preferences -> C/C++ -> Build -> Settings -> Discovery -> CDT GCC Build-in Compiler Settings
in the text box entitled Command to get compiler specs append -std=c++11
Now you can create project, configuration depends on what kind of project you created:
For project created as: File -> New -> Project -> C/C++ -> C++ Project
Right click on created project and open
Properties -> C/C++ Build -> Settings -> Tool Settings -> GCC C++ Compiler -> Dialect
Put -std=c++11 into text box entitled other dialect flags or select ISO C++11 from the Language standard drop down.
For CMake project
Generate eclipse project files (inside your project)
mkdir build cd build cmake -G"Eclipse CDT4 - Unix Makefiles" -D CMAKE_BUILD_TYPE=Debug .. Then import generated directory to eclipse as standard eclipse project. Right click project and open
Properties -> C/C++ General -> Preprocessor Include Paths, Marcos etc. -> Providers
enable CDT GCC Build-in Compiler Settings and move it higher than Contributed PathEntry Containers (This is important)
Last Common Step
recompile, regenerate Project ->C/C++ Index and restart Eclipse.
Update 2016:
As of gcc 6 (changes), the default C++ dialect is C++14. That means that unless you explicitly need a newer or older dialect than than, you don't need to do anything with eclipse anymore.
This community wiki section incorporates the answer by Trismegistos;
1. Before creating project, configure Eclipse syntax parser:
Window -> Preferences -> C/C++ -> Build -> Settings -> Discovery -> CDT GCC Build-in Compiler Settings
in the text box entitled Command to get compiler specs append -std=c++14 2. Create project, configuration depends on what kind of project you created:
For project created as: File -> New -> Project -> C/C++ -> C++ Project
Right click on created project and open
Properties -> C/C++ Build -> Settings -> Tool Settings -> GCC C++ Compiler -> Dialect
Put -std=c++14 into text box entitled other dialect flags or select ISO C++11 from the Language standard drop down.
For most recent versions: (Currently Juno and Kepler Luna):
Under newer versions of Juno the settings are located at Project properties -> C/C++ General -> Preprocessor Include Paths, Macros etc. -> tab Providers -> CDT GCC Builtin Compiler Settings ().
Older versions 2012/2013:
Under C/C++ Build (at project settings), find the Preprocessor Include Path and go to the Providers Tab. Deselect all except CDT GCC Builtin Compiler Settings. Then untag Share settings entries … . Add the option -std=c++11 to the text box called Command to get compiler specs.
Go to paths and symbols. Under Symbols, click restore defaults, and then apply.
Notes:
Eclipse is picky about hitting apply, you need to do it every time you leave a settings tab.
[Self-promotion]: I wrote my own more detailed instructions based on the above. http://scrupulousabstractions.tumblr.com/post/36441490955/eclipse-mingw-builds
Thanks to the user Nobody at https://stackoverflow.com/a/13635080/1149664
For the latest (Juno) eclipse cdt the following worked for me, no need to declare __GXX_EXPERIMENTAL_CXX0X__ on myself. This works for the the CDT indexer and as parameter for the compiler:
"your project name" -> right click -> properties:
C/C++ General -> Preprocessor Include Paths, Macros etc. -> switch to the tab named "Providers":
for "Configuration" select "Release" (and afterwards "debug")
switch off all providers and just select "CDT GCC Built-in Compiler Settings"
uncheck "Share setting entries between projects (global provider)"
in the "Command to get compiler specs:" add "-std=c++11" without the quotes (may work with quotes too)
hit apply and close the options
rebuild the index
Now all the c++11 related stuff should be resolved correctly by the indexer.
win7 x64, latest official eclipse with cdt mingw-w64 gcc 4.7.2 from the mingwbuilds project on sourceforge
I had the same problem on my Eclipse Juno. These steps solved the problem :
Project -> Properties -> C/C++ General -> Path and Symbols -> Tab [Symbols]. For Eclipse CDT Kepler what worked for me to get rid of std::thread unresolved symbol is:
Go to Preferences->C/C++->Build->Settings
Select the Discovery tab
Select CDT GCC Built-in Compiler Settings [Shared]
Add the -std=c++11 to the "Command to get the compiler specs:" field such as:
${COMMAND} -E -P -v -dD -std=c++11 ${INPUTS}
Adding -std=c++11 to project Properties/C/C++ Build->Settings->Tool Settings->GCC C++ Compiler->Miscellaneous->Other Flags wasn't enough for Kepler, however it was enough for older versions such as Helios.
I can't yet comment so am writing my own answer:
It's related to __GXX_EXPERIMENTAL_CXX0X__ and it's valid for Eclipse Juno and CDT 8.x.
Some parts of this answer are already covered in other answers but I want it to be coherent.
To make it possible to build using stdc++11, one have to add specific flag for compiler. You can do that via project properties. To modify project properties RMB andProject properties or ALT + ENTER. Then C/C++ Build -> Settings -> Tool Settings -> GCC C++ Compiler -> Miscellaneous -> Other Flags. Put -std=c++11 at the end of line, for GCC it will look something like: -c -fmessage-length=0 -std=c++11. By adding -stdc++11 flag compiler (GCC) will declare __GXX_EXPERIMENTAL_CXX0X__ by itself.
At this point you can build project using all the goodness of C++11.
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.
I had several issues too (Ubuntu 13.04 64-bit, g++-4.8, eclipse Juno 3.8.1, CDT 6.0.0). A lot of things are mentioned above, sorry to repeat those, but additionally I had problems utilizing
std::thread as part of c++11 (adding -pthread for the linker solves that issue). Anyway, finally these settings worked fine:
Project -> Properties -> C/C++ Build -> Settings -> Miscellaneous. Add the
-std=c++11 flag for the GCC and G++ compilers. Click Apply.
For the linker, same window, Miscellaneous, Linker flags, added the
-pthread flag. Shared library settings, Shared object name, add the
-Wl,--no-as-needed flag too. Click Apply.
C/C++ General -> Paths and symbols -> Symbols TAB, GNU C++ selected, Add the
__GXX_EXPERIMENTAL_CXX0X__ (no value)
flag. Click Apply.
C/C++ General -> Preprocessor Include paths.. -> Providers tab : check
CDT GCC built-in Compiler Settings
and for "Command to get compiler specs", add the
-std=c++11 flag. Uncheck Share. Click Apply.
CDT Managages Build Setting Entries, check this too. Uncheck the two others. Click Apply.
Going back to the Entries tab, GNU C++ CDT Managages Build Setting Entries, you should now see your added
__GXX_EXPERIMENTAL_CXX0X__ entry.
That's it. When coding, typing
std:: can now auto-complete the thread class for instance, builds should work fine and there should be no
std::system_error'what(): Enable multithreading to use std::thread: Operation not permitted at runtime.
I don't know if it is only me, the highest ranked solution doesn't work for me, my eclipse version is just normal eclipse platform installed by using sudo apt-get install eclipse in Ubuntu But I found a solution which adopts method together from both the highest ranked solution and the second, what I did to make it work is described as below (Note that the other steps like creating a C++ project etc. is ignored for simplicity)
Once you have created the C++ project
(1) 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.
(2) Under C/C++ Build (at project settings), find the Preprocessor Include Path and go to the Providers Tab. Deselect all except CDT GCC Builtin Compiler Settings. Then untag Share settings entries … . Add the option -std=c++11 to the text box called Command to get compiler specs
After performed above 2 and 2 only steps, it works, the eclipse is able to resolve the unique_ptr, I don't know why this solution works, hope that it can help people.
For me on Eclipse Neon I followed Trismegistos answer here above , YET I also added an additional step:
Hit apply and OK.
Cheers,
Guy.
Neither the hack nor the cleaner version work for Indigo. The hack is ignored, and the required configuration options are missing. For no apparent reason, build started working after not working and not providing any useful reason why. At least from the command line, I get reproducible results.
To get support for C++14 in Eclipse Luna, you could do these steps:
C++ General -> Preprocessor Include -> Providers -> CDT Cross GCC Built-in Compiler Settings, add "-std=c++14"C++ Build -> Settings -> Cross G++ Compiler -> Miscellaneous, add "-std=c++14"Reindex your project and eventually restart Eclipse. It should work as expected.
Eclipse C/C++ does not recognize the symbol std::unique_ptr even though you have included the C++11 memory header in your file.
Assuming you are using the GNU C++ compiler, this is what I did to fix:
Project -> Properties -> C/C++ General -> Preprocessor Include Paths -> GNU C++ -> CDT User Setting Entries
Click on the "Add..." button
Select "Preprocessor Macro" from the dropdown menu
Name: __cplusplus Value: 201103L Hit Apply, and then OK to go back to your project
Then rebuild you C++ index: Projects -> C/C++ Index -> Rebuild