For the purposes of portability, there are some restrictions on C++ usage. Here are the things not to do, and the justification for why.
While it would be great to use the latest and greatest language features, unfortunately embedded target platforms like the Dreamcast, PSP, etc. do not have compiler chains that support them well.
Amazing as the C++11 threading libraries are, they are not well supported in the Dreamcast and PSP homebrew toolchains. Instead use the threading subsystems in simulant/thread.