In our CentOS 6.6 system we have a nonstandard gcc installation - let's say it's /opt/gcc49 - and the "standard" gcc installation as well, both with their own includes and libstdc++.
There's an option in icpc command, -cxxlib, which can be used to define the directory for C++ standard library. Using -cxxlib=/opt/gcc49 option helps with header files, but not with libstdc++ - even with this option it still takes /usr/lib/libstdc++.a instead of /opt/gcc49/lib/libstdc++.a
Passing the correct libstdc++ path to the command line helps as a workaround, but this hardly integrates with automated build tools.