615 lines
19 KiB
C++
615 lines
19 KiB
C++
// Output streams -*- C++ -*-
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// Copyright (C) 1997-2013 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/** @file include/ostream
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* This is a Standard C++ Library header.
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*/
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//
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// ISO C++ 14882: 27.6.2 Output streams
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//
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#ifndef _GLIBCXX_OSTREAM
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#define _GLIBCXX_OSTREAM 1
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#pragma GCC system_header
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#include <ios>
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#include <bits/ostream_insert.h>
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namespace std _GLIBCXX_VISIBILITY(default)
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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/**
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* @brief Template class basic_ostream.
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* @ingroup io
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*
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* @tparam _CharT Type of character stream.
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* @tparam _Traits Traits for character type, defaults to
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* char_traits<_CharT>.
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*
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* This is the base class for all output streams. It provides text
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* formatting of all builtin types, and communicates with any class
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* derived from basic_streambuf to do the actual output.
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*/
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template<typename _CharT, typename _Traits>
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class basic_ostream : virtual public basic_ios<_CharT, _Traits>
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{
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public:
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// Types (inherited from basic_ios):
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typedef _CharT char_type;
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typedef typename _Traits::int_type int_type;
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typedef typename _Traits::pos_type pos_type;
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typedef typename _Traits::off_type off_type;
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typedef _Traits traits_type;
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// Non-standard Types:
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typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
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typedef basic_ios<_CharT, _Traits> __ios_type;
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typedef basic_ostream<_CharT, _Traits> __ostream_type;
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typedef num_put<_CharT, ostreambuf_iterator<_CharT, _Traits> >
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__num_put_type;
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typedef ctype<_CharT> __ctype_type;
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/**
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* @brief Base constructor.
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*
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* This ctor is almost never called by the user directly, rather from
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* derived classes' initialization lists, which pass a pointer to
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* their own stream buffer.
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*/
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explicit
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basic_ostream(__streambuf_type* __sb)
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{ this->init(__sb); }
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/**
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* @brief Base destructor.
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*
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* This does very little apart from providing a virtual base dtor.
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*/
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virtual
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~basic_ostream() { }
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/// Safe prefix/suffix operations.
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class sentry;
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friend class sentry;
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//@{
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/**
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* @brief Interface for manipulators.
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*
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* Manipulators such as @c std::endl and @c std::hex use these
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* functions in constructs like "std::cout << std::endl". For more
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* information, see the iomanip header.
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*/
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__ostream_type&
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operator<<(__ostream_type& (*__pf)(__ostream_type&))
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// DR 60. What is a formatted input function?
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// The inserters for manipulators are *not* formatted output functions.
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return __pf(*this);
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}
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__ostream_type&
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operator<<(__ios_type& (*__pf)(__ios_type&))
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// DR 60. What is a formatted input function?
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// The inserters for manipulators are *not* formatted output functions.
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__pf(*this);
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return *this;
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}
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__ostream_type&
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operator<<(ios_base& (*__pf) (ios_base&))
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// DR 60. What is a formatted input function?
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// The inserters for manipulators are *not* formatted output functions.
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__pf(*this);
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return *this;
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}
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//@}
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//@{
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/**
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* @name Inserters
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*
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* All the @c operator<< functions (aka <em>formatted output
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* functions</em>) have some common behavior. Each starts by
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* constructing a temporary object of type std::basic_ostream::sentry.
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* This can have several effects, concluding with the setting of a
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* status flag; see the sentry documentation for more.
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*
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* If the sentry status is good, the function tries to generate
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* whatever data is appropriate for the type of the argument.
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*
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* If an exception is thrown during insertion, ios_base::badbit
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* will be turned on in the stream's error state without causing an
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* ios_base::failure to be thrown. The original exception will then
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* be rethrown.
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*/
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//@{
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/**
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* @brief Integer arithmetic inserters
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* @param __n A variable of builtin integral type.
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* @return @c *this if successful
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*
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* These functions use the stream's current locale (specifically, the
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* @c num_get facet) to perform numeric formatting.
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*/
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__ostream_type&
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operator<<(long __n)
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{ return _M_insert(__n); }
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__ostream_type&
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operator<<(unsigned long __n)
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{ return _M_insert(__n); }
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__ostream_type&
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operator<<(bool __n)
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{ return _M_insert(__n); }
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__ostream_type&
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operator<<(short __n);
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__ostream_type&
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operator<<(unsigned short __n)
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// 117. basic_ostream uses nonexistent num_put member functions.
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return _M_insert(static_cast<unsigned long>(__n));
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}
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__ostream_type&
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operator<<(int __n);
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__ostream_type&
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operator<<(unsigned int __n)
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// 117. basic_ostream uses nonexistent num_put member functions.
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return _M_insert(static_cast<unsigned long>(__n));
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}
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#ifdef _GLIBCXX_USE_LONG_LONG
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__ostream_type&
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operator<<(long long __n)
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{ return _M_insert(__n); }
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__ostream_type&
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operator<<(unsigned long long __n)
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{ return _M_insert(__n); }
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#endif
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//@}
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//@{
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/**
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* @brief Floating point arithmetic inserters
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* @param __f A variable of builtin floating point type.
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* @return @c *this if successful
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*
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* These functions use the stream's current locale (specifically, the
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* @c num_get facet) to perform numeric formatting.
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*/
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__ostream_type&
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operator<<(double __f)
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{ return _M_insert(__f); }
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__ostream_type&
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operator<<(float __f)
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{
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// _GLIBCXX_RESOLVE_LIB_DEFECTS
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// 117. basic_ostream uses nonexistent num_put member functions.
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return _M_insert(static_cast<double>(__f));
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}
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__ostream_type&
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operator<<(long double __f)
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{ return _M_insert(__f); }
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//@}
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/**
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* @brief Pointer arithmetic inserters
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* @param __p A variable of pointer type.
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* @return @c *this if successful
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*
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* These functions use the stream's current locale (specifically, the
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* @c num_get facet) to perform numeric formatting.
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*/
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__ostream_type&
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operator<<(const void* __p)
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{ return _M_insert(__p); }
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/**
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* @brief Extracting from another streambuf.
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* @param __sb A pointer to a streambuf
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*
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* This function behaves like one of the basic arithmetic extractors,
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* in that it also constructs a sentry object and has the same error
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* handling behavior.
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*
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* If @p __sb is NULL, the stream will set failbit in its error state.
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*
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* Characters are extracted from @p __sb and inserted into @c *this
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* until one of the following occurs:
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*
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* - the input stream reaches end-of-file,
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* - insertion into the output sequence fails (in this case, the
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* character that would have been inserted is not extracted), or
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* - an exception occurs while getting a character from @p __sb, which
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* sets failbit in the error state
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*
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* If the function inserts no characters, failbit is set.
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*/
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__ostream_type&
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operator<<(__streambuf_type* __sb);
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//@}
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//@{
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/**
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* @name Unformatted Output Functions
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*
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* All the unformatted output functions have some common behavior.
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* Each starts by constructing a temporary object of type
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* std::basic_ostream::sentry. This has several effects, concluding
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* with the setting of a status flag; see the sentry documentation
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* for more.
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*
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* If the sentry status is good, the function tries to generate
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* whatever data is appropriate for the type of the argument.
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*
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* If an exception is thrown during insertion, ios_base::badbit
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* will be turned on in the stream's error state. If badbit is on in
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* the stream's exceptions mask, the exception will be rethrown
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* without completing its actions.
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*/
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/**
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* @brief Simple insertion.
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* @param __c The character to insert.
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* @return *this
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*
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* Tries to insert @p __c.
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*
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* @note This function is not overloaded on signed char and
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* unsigned char.
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*/
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__ostream_type&
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put(char_type __c);
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/**
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* @brief Core write functionality, without sentry.
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* @param __s The array to insert.
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* @param __n Maximum number of characters to insert.
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*/
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void
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_M_write(const char_type* __s, streamsize __n)
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{
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const streamsize __put = this->rdbuf()->sputn(__s, __n);
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if (__put != __n)
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this->setstate(ios_base::badbit);
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}
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/**
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* @brief Character string insertion.
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* @param __s The array to insert.
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* @param __n Maximum number of characters to insert.
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* @return *this
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*
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* Characters are copied from @p __s and inserted into the stream until
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* one of the following happens:
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*
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* - @p __n characters are inserted
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* - inserting into the output sequence fails (in this case, badbit
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* will be set in the stream's error state)
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*
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* @note This function is not overloaded on signed char and
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* unsigned char.
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*/
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__ostream_type&
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write(const char_type* __s, streamsize __n);
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//@}
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/**
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* @brief Synchronizing the stream buffer.
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* @return *this
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*
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* If @c rdbuf() is a null pointer, changes nothing.
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*
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* Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
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* sets badbit.
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*/
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__ostream_type&
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flush();
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/**
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* @brief Getting the current write position.
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* @return A file position object.
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*
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* If @c fail() is not false, returns @c pos_type(-1) to indicate
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* failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
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*/
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pos_type
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tellp();
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/**
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* @brief Changing the current write position.
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* @param __pos A file position object.
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* @return *this
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*
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* If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos). If
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* that function fails, sets failbit.
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*/
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__ostream_type&
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seekp(pos_type);
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/**
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* @brief Changing the current write position.
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* @param __off A file offset object.
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* @param __dir The direction in which to seek.
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* @return *this
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*
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* If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
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* If that function fails, sets failbit.
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*/
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__ostream_type&
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seekp(off_type, ios_base::seekdir);
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protected:
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basic_ostream()
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{ this->init(0); }
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template<typename _ValueT>
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__ostream_type&
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_M_insert(_ValueT __v);
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};
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/**
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* @brief Performs setup work for output streams.
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*
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* Objects of this class are created before all of the standard
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* inserters are run. It is responsible for <em>exception-safe prefix and
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* suffix operations</em>.
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*/
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template <typename _CharT, typename _Traits>
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class basic_ostream<_CharT, _Traits>::sentry
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{
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// Data Members.
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bool _M_ok;
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basic_ostream<_CharT, _Traits>& _M_os;
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public:
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/**
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* @brief The constructor performs preparatory work.
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* @param __os The output stream to guard.
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*
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* If the stream state is good (@a __os.good() is true), then if the
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* stream is tied to another output stream, @c is.tie()->flush()
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* is called to synchronize the output sequences.
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*
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* If the stream state is still good, then the sentry state becomes
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* true (@a okay).
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*/
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explicit
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sentry(basic_ostream<_CharT, _Traits>& __os);
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/**
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* @brief Possibly flushes the stream.
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*
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* If @c ios_base::unitbuf is set in @c os.flags(), and
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* @c std::uncaught_exception() is true, the sentry destructor calls
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* @c flush() on the output stream.
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*/
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~sentry()
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{
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// XXX MT
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if (bool(_M_os.flags() & ios_base::unitbuf) && !uncaught_exception())
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{
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// Can't call flush directly or else will get into recursive lock.
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if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
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_M_os.setstate(ios_base::badbit);
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}
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}
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/**
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* @brief Quick status checking.
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* @return The sentry state.
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*
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* For ease of use, sentries may be converted to booleans. The
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* return value is that of the sentry state (true == okay).
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*/
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#if __cplusplus >= 201103L
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explicit
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#endif
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operator bool() const
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{ return _M_ok; }
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};
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//@{
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/**
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* @brief Character inserters
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* @param __out An output stream.
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* @param __c A character.
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* @return out
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*
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* Behaves like one of the formatted arithmetic inserters described in
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* std::basic_ostream. After constructing a sentry object with good
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* status, this function inserts a single character and any required
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* padding (as determined by [22.2.2.2.2]). @c __out.width(0) is then
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* called.
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*
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* If @p __c is of type @c char and the character type of the stream is not
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* @c char, the character is widened before insertion.
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*/
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template<typename _CharT, typename _Traits>
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inline basic_ostream<_CharT, _Traits>&
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operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
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{ return __ostream_insert(__out, &__c, 1); }
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template<typename _CharT, typename _Traits>
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inline basic_ostream<_CharT, _Traits>&
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operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
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{ return (__out << __out.widen(__c)); }
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// Specialization
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template <class _Traits>
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inline basic_ostream<char, _Traits>&
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operator<<(basic_ostream<char, _Traits>& __out, char __c)
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{ return __ostream_insert(__out, &__c, 1); }
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// Signed and unsigned
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template<class _Traits>
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inline basic_ostream<char, _Traits>&
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operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
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{ return (__out << static_cast<char>(__c)); }
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template<class _Traits>
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inline basic_ostream<char, _Traits>&
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operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
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{ return (__out << static_cast<char>(__c)); }
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//@}
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//@{
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/**
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* @brief String inserters
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* @param __out An output stream.
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* @param __s A character string.
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* @return out
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* @pre @p __s must be a non-NULL pointer
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*
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* Behaves like one of the formatted arithmetic inserters described in
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* std::basic_ostream. After constructing a sentry object with good
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* status, this function inserts @c traits::length(__s) characters starting
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* at @p __s, widened if necessary, followed by any required padding (as
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* determined by [22.2.2.2.2]). @c __out.width(0) is then called.
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*/
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template<typename _CharT, typename _Traits>
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inline basic_ostream<_CharT, _Traits>&
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operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
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{
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if (!__s)
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__out.setstate(ios_base::badbit);
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else
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__ostream_insert(__out, __s,
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static_cast<streamsize>(_Traits::length(__s)));
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return __out;
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}
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template<typename _CharT, typename _Traits>
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basic_ostream<_CharT, _Traits> &
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operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);
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|
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// Partial specializations
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template<class _Traits>
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inline basic_ostream<char, _Traits>&
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operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
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{
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if (!__s)
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__out.setstate(ios_base::badbit);
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else
|
|
__ostream_insert(__out, __s,
|
|
static_cast<streamsize>(_Traits::length(__s)));
|
|
return __out;
|
|
}
|
|
|
|
// Signed and unsigned
|
|
template<class _Traits>
|
|
inline basic_ostream<char, _Traits>&
|
|
operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
|
|
{ return (__out << reinterpret_cast<const char*>(__s)); }
|
|
|
|
template<class _Traits>
|
|
inline basic_ostream<char, _Traits> &
|
|
operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
|
|
{ return (__out << reinterpret_cast<const char*>(__s)); }
|
|
//@}
|
|
|
|
// Standard basic_ostream manipulators
|
|
|
|
/**
|
|
* @brief Write a newline and flush the stream.
|
|
*
|
|
* This manipulator is often mistakenly used when a simple newline is
|
|
* desired, leading to poor buffering performance. See
|
|
* http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
|
|
* for more on this subject.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
inline basic_ostream<_CharT, _Traits>&
|
|
endl(basic_ostream<_CharT, _Traits>& __os)
|
|
{ return flush(__os.put(__os.widen('\n'))); }
|
|
|
|
/**
|
|
* @brief Write a null character into the output sequence.
|
|
*
|
|
* <em>Null character</em> is @c CharT() by definition. For CharT
|
|
* of @c char, this correctly writes the ASCII @c NUL character
|
|
* string terminator.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
inline basic_ostream<_CharT, _Traits>&
|
|
ends(basic_ostream<_CharT, _Traits>& __os)
|
|
{ return __os.put(_CharT()); }
|
|
|
|
/**
|
|
* @brief Flushes the output stream.
|
|
*
|
|
* This manipulator simply calls the stream's @c flush() member function.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
inline basic_ostream<_CharT, _Traits>&
|
|
flush(basic_ostream<_CharT, _Traits>& __os)
|
|
{ return __os.flush(); }
|
|
|
|
#if __cplusplus >= 201103L
|
|
/**
|
|
* @brief Generic inserter for rvalue stream
|
|
* @param __os An input stream.
|
|
* @param __x A reference to the object being inserted.
|
|
* @return os
|
|
*
|
|
* This is just a forwarding function to allow insertion to
|
|
* rvalue streams since they won't bind to the inserter functions
|
|
* that take an lvalue reference.
|
|
*/
|
|
template<typename _CharT, typename _Traits, typename _Tp>
|
|
inline basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>&& __os, const _Tp& __x)
|
|
{
|
|
__os << __x;
|
|
return __os;
|
|
}
|
|
#endif // C++11
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace std
|
|
|
|
#include <bits/ostream.tcc>
|
|
|
|
#endif /* _GLIBCXX_OSTREAM */
|