John Kalane questions

• What is the exact meaning of the statement "The expression e is used as a glvalue if and only if the initialization uses it as a glvalue" in [conv]/6
• What can go wrong if cout.rdbuf() is used to switch buffer and never set it back?
• What's the difference between a tracked and a staged file?
• Difference between basic_istream<>::tellg() and basic_ostream<>::tellp() [closed]
• Apparent contradiction between Stroustrup book and the C++Standard

John Kalane answers