std::string not being resolved in Eclipse/CDT 8.0

Seemed to have worked fine in CDT 7.0 in Eclipse Helios, but since upgrading I'm getting a l开发者_如何学JAVAot of unresolved symbols in my C++ projects, namely a lot of STL classes.

I used to have the same problem with CDT 8, but then they got automatically resolved and now it all works perfectly. I think holding a cursor above the #includes and using directives tells eclipse to scan those namespaces and includes and to stop showing those errors.

There is an indexer option "Index source and header files opened in editor" and it seems to be deactivated by default. By activating it, I got rid of "all unresolved when opening a file" and "staying unresolved after building".