Where are the man pages for C++?
Does documentation for C++ exist in Linux? I want something like the man pages of C. For example, docs for string, stl, iostream, ifstream, etc.?
Answer
If you use the "normal" libstdc++ shipped with g++, its documentation is available online here.
Most Linux distributions make it also available offline as a particular package; for Debian-derived distros, for example, it's libstdc++-6-<version>-doc (e.g. on my Ubuntu machine I have libstdc++-6-4.4-doc installed). In general the documentation will be put somewhere like /usr/share/doc/libstdc++-6-4.4-doc.
This about implementation-specific documentation; for compiler-agnostic docs, instead, many sites on the Internet provide reference documentation for the standard library. One of the most referenced is cplusplus.com, that however is known to contain several errors in its documentation; also the C++ library section on msdn.microsoft.com has got much better in the recent years in separating what are the Microsoft-specific details from what the standard dictates.
Finally, if you want precision up to the paranoia, the ultimate normative document is the C++ standard, that is sold from ISO, ANSI and BSI (for a quite high price); there are however several drafts available for free, which are more than good enough for "casual use".