C++ Error 'nullptr was not declared in this scope' in Eclipse IDE

Vivek Ragunathan picture Vivek Ragunathan · Apr 5, 2012 · Viewed 173.9k times · Source

I am running Eclipse Helios and I have g++-4.6 installed. Hope I am not wrong that g++4.6 implements C++ 11 features. I have created a C++ project which uses the nullptr and auto keywords. The build gives the following errors:-

../{filename}.cpp:13:13: error: ‘nullptr’ was not declared in this scope

../{filename}.cpp:14:2: warning: ‘auto’ will change meaning in C++0x; please remove it [-Wc++0x-compat]

Actually it was building fine until yesterday. I am getting these from nowhere today. Please help me solve this problem.

Answer

Rob I picture Rob I · Apr 5, 2012

According to the GCC page for C++11:

To enable C++0x support, add the command-line parameter -std=c++0x to your g++ command line. Or, to enable GNU extensions in addition to C++0x extensions, add -std=gnu++0x to your g++ command line. GCC 4.7 and later support -std=c++11 and -std=gnu++11 as well.

Did you compile with -std=gnu++0x ?