If anyone's as annoyed as I am by the libstdc++.so.6 warning that building a C++ project gives, here's what you can do.
Add a new error parser with the pattern
Code:
.*?libstdc\+\+\.so\.6, needed by.*
set to "Ignore"
Enable the parser in your project and move it to the top.
This prevents Eclipse from registering the warning in the problems view and on your project icon.