gcc .map lists both libstdc++.so and libcpp.so - which one will be used for string, vector, etc

Question

My .map file for the gcc linker output contains both libstdc++.so and libcpp.so and I've read that they're incompatible

How will it know which C++ lib to select?
If this executable instantiates a string then passes it to another executable that also has both libstdc++ and libcpp in .map file . . . will things work out?

Documentation is appreciated.