How to enable C++11/C++0x support in Eclipse CDT?

Question

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<char[]>(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?

Answer 1

For me on Eclipse Neon I followed Trismegistos answer here above , YET I also added an additional step:

• Go to project --> Properties --> C++ General --> Preprocessor Include paths,Macros etc. --> Providers --> CDT Cross GCC Built-in Compiler Settings, append the flag "-std=c++11"

Hit apply and OK.

Cheers,

Guy.

Answer 2

Instruction For Eclipse CDT 4.4 Luna and 4.5 Mars

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.

Answer 3

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

1. Click on the "Add..." button

2. Select "Preprocessor Macro" from the dropdown menu

   Name: __cplusplus     Value:  201103L
   

3. Hit Apply, and then OK to go back to your project

4. Then rebuild you C++ index: Projects -> C/C++ Index -> Rebuild