This makes no sense. As I said the original poster was saying that g++ and libstdc++ are tangled together and it is not possible to use g++ with another impleme

This makes no sense. As I said the original poster was saying that g++ and libstdc++ are tangled together and it is not possible to use g++ with another implementation of the C++ libraries. But you can use gcc with other C libraries. As proven by gcc running on other OSs with non glibc libraries. If anything isn't "independent" here (using your definition) it's the apps that rely on implementation detail - not the C library, the C programming language, or the compiler.