This question was asked many times and I failed to replicate all of the solutions I could find. I am unable to find this setting under File->Project Settings (as some sugges
Build Settings -> Linking-> other linker flags -> add to "-lc++"
It's the same for 7 and 8. From the Project Navigator, select the project. In the main panel, at the top left, select the target. Now the main panel should have General, Resource Tags, Build Settings, Build Phases, & Build Rules along the top. Select Build Settings, select All. Scroll down to "Apple LLVM 8.0 Language C++" and expand it. Change "C++ Language Dialect" to "C++11 [-std=c++11]".