I found that the 2013 XE has a new option -use-clang-env that will cause icpc/icc to use clang to steup the environment. But I tried it out, it seems no effect at all. Even in C++11 mode, stil the old libstc++ distributed with llvm-gcc-4.2 is used.
However, Apple is going to remove llvm-gcc in furture release of Xcode. Does that mean that, once that happens, icpc will have to use clang to set up environemnt, and use libc++ instead?
Is there anyway to have icpc work with clang's libc++ at the moment? The old libstdc++ provides no C++11 support at all. So turn on -std=c++11 only enables some language features .