Standard library header - cppreference.com (original) (raw)

This header is part of the Input/output library.

Including <iostream> behaves as if it defines a static storage duration object of type std::ios_base::Init, whose constructor initializes the standard stream objects if it is the first std::ios_base::Init object to be constructed, and whose destructor flushes those objects (except for cin and wcin) if it is the last std::ios_base::Init object to be destroyed.

[edit] Synopsis

#include #include #include #include   namespace std { extern istream cin; extern ostream cout; extern ostream cerr; extern ostream clog;   extern wistream wcin; extern wostream wcout; extern wostream wcerr; extern wostream wclog; }

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 155 C++98 the type of the static object was std::basic_ios::Init(not strictly wrong, but the wording was misleading) corrected to std::ios_base::Init
LWG 1123 C++98 including did not guarantee theconstruction of std::ios_base::Init objects guarantees