G++ compiler has the feature to auto include libstdc++ when needed. Particle use a nano version of this library to minimize the size, but it still too big and does not fit on flash memory (at least for particle and photon). This makes us, the users, unable to use some features of standard library, like iostreams.
I have the suggestion how to partly solve this problem.
Since linking of stdlib is not possible anyway it would help to include additional linking flag, -nostdlib, disabling linkage of stdlib. This way missing definitions can be copy-pasted to separate libraries, for example for iostream. And depending what is used include these libraries.