超经典的C++ iostream库源码分享给大家，可供学习和使用！

// -*- C++ -*-
//===--------------------------- iostream ---------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_IOSTREAM
#define _LIBCPP_IOSTREAM



#include <ios>
#include <streambuf>
#include <istream>
#include <ostream>

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;

}  // std


#include <__config>
#include <ios>
#include <streambuf>
#include <istream>
#include <ostream>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#ifndef _LIBCPP_HAS_NO_STDIN
extern _LIBCPP_FUNC_VIS istream cin;
extern _LIBCPP_FUNC_VIS wistream wcin;
#endif
#ifndef _LIBCPP_HAS_NO_STDOUT
extern _LIBCPP_FUNC_VIS ostream cout;
extern _LIBCPP_FUNC_VIS wostream wcout;
#endif
extern _LIBCPP_FUNC_VIS ostream cerr;
extern _LIBCPP_FUNC_VIS wostream wcerr;
extern _LIBCPP_FUNC_VIS ostream clog;
extern _LIBCPP_FUNC_VIS wostream wclog;

_LIBCPP_END_NAMESPACE_STD

#endif  // _LIBCPP_IOSTREAM