How do I change the c++ standard Library used by XCode?

Im currently trying to build a chess app with a chess engine plugin that has been coded in c++.

The engine has been coded using c++17 features in a few areas, which is making the Xcode builds fail. I've tried changing the c++ language dialect to c++17, but this hasn't helped with the library issues. Ive seen some guides show that there is an option to set the c++ library, but I cannot find this anywhere.

Any help would be much appreciated.

Click on your Xcode project file (the one at the top of the file browser in Xcode), then click on the Build Settings tab. Scroll down to "Apple Clang - Language - C++". There is an option to change the language dialect - you can change the version of c++ used, as well as the libc++ used.

Could it be caused by this project being built in the unity engine first and then is using a Xcode plugin that has this c++ code?

I'm getting pretty confused and frustrated with this problem as I cannot see why Xcode is not using c++14 or c++17 features.

Both std::optional and std::enable_if_t work fine. You have to set the standard to C++17. There is no need to change the C++ library.

How do I change the c++ standard Library used by XCode?
 
 
Q