This is a straight port of uClibc++ for Arduino. I have cut nothing out and held nothing back. Use with care!
That said, I have used uClibc++'s own internal configuration to pare back un-needed stuff, like support for floats, gratuitous template instantiations and other things. See system_configuration.h for all of those gory details.
Plus I added in Andy Brown's excellent ohserialstream class for managing the HardwareSerial as an ostream.
This is installed just like a regular Arduino library. Unpack the contents of the distribution into the 'libraries' folder under your sketchbook. For example, my sketchbook is at /home/maniacbug/Source/Arduino, so this library is in /home/maniacbug/Source/Arduino/libraries/StandardCplusplus .
Be sure to reset your Arduino IDE after installing it.
From the Arduino IDE, navigate the menus to: File > Examples > StandardCplusplus > string_vector
Upload that, set your serial monitor to 57600 baud, and check the output.
The web is your friend. cplusplus.com is my personal favorite reference.
Arduino 1.0 and beyond.
uClibc++ is LGPL, so this port is also. Andy's file is actually CC-BY-SA, however he indicated he'd be releasing it using the 3-clause modified BSD license, so it will be fully compatible with uClibc++.