The standard library for C++ (STL) contains a comprehensive and ever-growing collection of functions, classes, and more that allows for common tasks to be performed without having to rely on external libraries. The STL string class is very popular, and allows you to safely handle strings without having to deal with null terminators and anything similar.
Most embedded platforms support all or at least a significant part of the STL, barring limitations on available RAM and the like that prevent the implementation of full hash tables and other complex data structures. Many embedded STL implementations contain optimizations for the target platform, minimizing RAM and CPU usage.