Eclipse CDT Indexer does not fully recognize c++11

Question

First of all, I know about the -std=c++11 flag to enable c++11 support and where to place it. I've appended -std=c++11 to Project -> Properties -> C/C++ Build -> Settings -> Tool Settings -> GCC C++ Compiler -> Miscellaneous -> Other Flags and compiling just works fine. But the indexer doesn't get along, for example if I want to use the emplace function of std::map (c++11), it will not find the emplace function.

#include <map>

int main() {
    std::map<int, int> data;
    data.emplace(5,5);

I've also checked out these related questions:

• Eclipse CDT indexer does not know C++11 containers
• Enable C++11 in Eclipse CDT (Juno/Kepler/Luna) indexer
• http://www.eclipse.org/forums/index.php/mv/msg/373462/909018/#msg_909018

Update: Now that I've played around it even doesn't recognize the std::map type, although compiling fine and eclipse finding all headers...

• Compiler Mingw64 GCC 5.2.0
• Eclipse Mars 4.5
• CDT 8.7

Answer 1

Eclipse Mars does it a bit differently than the previous versions.

Step one gets the indexer error highlighting working - covered in Enable C++11 in Eclipse CDT (Juno/Kepler/Luna) indexer linked above. If you've already done all this, I'll be smurfed if I know what you've run into. Mars has been a bit wonky so far.

1. Go to Project->properties->C/C++ General->Preprocessor Include Paths.
2. Click the Providers tab.
3. Click CDT GCC Built-in Compiler settings MinGW
4. Click Move Up button on the right.
5. Under Language Settings Provider Options
   1. Click off Use Global provider shared between projects
   2. Add -std=c++1y to the end of the command line in Command to get compiler specs.

By the way, if anyone knows where the global settings are so I can default this behaviour, please let me know.

Step 2 gets the compiler working

1. Go to Project->properties->C/C++ Build->Settings.
2. Go to Tool Settings tab.
3. Expand GCC C++ Compiler
4. Click Dialect Pick the C++ Standard you wish to target from the Language Standard drop-down.

Answer 2

Eclipse CDT understands the C++ code in a window by running it through an indexer. This indexer is nothing but an invocation of the GCC C++ compiler with certain compilation options. Sometimes, you might want to change the compiler options used by this indexer.

For example, I recently found that C++11 containers and classes (like future) were not resolved by the indexer and were underlined with red squiggles. This is because the compiler options used by the indexer does not have -std=c++11.

To change the compiler options of the indexer:

1. Open Preferences and go to C/C++ -> Build -> Settings.
2. Click the Discovery tab and choose CDT GCC Built-in Compiler Settings.
3. Modify the command string shown below it as you wish. For example, here I added -std=c++11.
4. Eclipse CDT will automatically re-index your C++ files after this is saved. However, I found that this did not remove the unresolved items.
5. I manually re-indexed by right-clicking the project and choosing Index -> Rebuild. This worked!