#include <stream> not working on win or mac

If I install a new build of platformIO and build a sample then add #include

I get a fatal error saying string No such file or directory.

I cannot see a path setting to resolve the include directories, and even then which directory should it point to.
I see use -l stdc++ and - x c++ and -std=c++11 to add to build_flags none of these changed this

I want to use a range of std functions and templates… but it seems that atom just fails every time I try to use them…

Any ideas