998 lines
32 KiB
C++
998 lines
32 KiB
C++
// Input streams -*- C++ -*-
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// Copyright (C) 1997-2022 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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//
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// ISO C++ 14882: 27.6.1 Input streams
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//
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/** @file include/istream
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* This is a Standard C++ Library header.
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*/
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#ifndef _GLIBCXX_ISTREAM
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#define _GLIBCXX_ISTREAM 1
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#pragma GCC system_header
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#include <ios>
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#include <ostream>
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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_istream.
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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 input 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 input.
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*/
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template<typename _CharT, typename _Traits>
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class basic_istream : virtual public basic_ios<_CharT, _Traits>
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{
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public:
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// Types (inherited from basic_ios (27.4.4)):
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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_istream<_CharT, _Traits> __istream_type;
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typedef num_get<_CharT, istreambuf_iterator<_CharT, _Traits> >
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__num_get_type;
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typedef ctype<_CharT> __ctype_type;
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protected:
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// Data Members:
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/**
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* The number of characters extracted in the previous unformatted
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* function; see gcount().
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*/
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streamsize _M_gcount;
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public:
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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_istream(__streambuf_type* __sb)
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: _M_gcount(streamsize(0))
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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_istream()
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{ _M_gcount = streamsize(0); }
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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::ws and @c std::dec use these
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* functions in constructs like
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* <code>std::cin >> std::ws</code>.
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* For more information, see the iomanip header.
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*/
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__istream_type&
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operator>>(__istream_type& (*__pf)(__istream_type&))
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{ return __pf(*this); }
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__istream_type&
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operator>>(__ios_type& (*__pf)(__ios_type&))
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{
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__pf(*this);
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return *this;
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}
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__istream_type&
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operator>>(ios_base& (*__pf)(ios_base&))
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{
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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 Extractors
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*
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* All the @c operator>> functions (aka <em>formatted input
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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_istream::sentry
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* with the second argument (noskipws) set to false. This has several
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* effects, concluding with the setting of a status flag; see the
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* sentry documentation for more.
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*
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* If the sentry status is good, the function tries to extract
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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 extraction, 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) and the original exception will
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* be rethrown if badbit is set in the exceptions mask.
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*/
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///@{
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/**
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* @brief Integer arithmetic extractors
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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 parse the input data.
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*/
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__istream_type&
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operator>>(bool& __n)
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{ return _M_extract(__n); }
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__istream_type&
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operator>>(short& __n);
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__istream_type&
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operator>>(unsigned short& __n)
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{ return _M_extract(__n); }
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__istream_type&
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operator>>(int& __n);
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__istream_type&
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operator>>(unsigned int& __n)
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{ return _M_extract(__n); }
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__istream_type&
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operator>>(long& __n)
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{ return _M_extract(__n); }
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__istream_type&
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operator>>(unsigned long& __n)
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{ return _M_extract(__n); }
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#ifdef _GLIBCXX_USE_LONG_LONG
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__istream_type&
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operator>>(long long& __n)
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{ return _M_extract(__n); }
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__istream_type&
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operator>>(unsigned long long& __n)
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{ return _M_extract(__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 extractors
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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 parse the input data.
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*/
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__istream_type&
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operator>>(float& __f)
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{ return _M_extract(__f); }
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__istream_type&
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operator>>(double& __f)
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{ return _M_extract(__f); }
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__istream_type&
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operator>>(long double& __f)
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{ return _M_extract(__f); }
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///@}
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/**
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* @brief Basic arithmetic extractors
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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 parse the input data.
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*/
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__istream_type&
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operator>>(void*& __p)
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{ return _M_extract(__p); }
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/**
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* @brief Extracting into 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 this stream and inserted into the
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* @p __sb streambuf 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 buffer 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 (and in this case is caught)
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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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__istream_type&
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operator>>(__streambuf_type* __sb);
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///@}
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// [27.6.1.3] unformatted input
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/**
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* @brief Character counting
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* @return The number of characters extracted by the previous
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* unformatted input function dispatched for this stream.
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*/
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streamsize
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gcount() const
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{ return _M_gcount; }
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///@{
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/**
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* @name Unformatted Input Functions
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*
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* All the unformatted input functions have some common behavior.
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* Each starts by constructing a temporary object of type
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* std::basic_istream::sentry with the second argument (noskipws)
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* set to true. This has several effects, concluding with the
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* setting of a 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 extract
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* whatever data is appropriate for the type of the argument.
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*
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* The number of characters extracted is stored for later retrieval
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* by gcount().
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*
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* If an exception is thrown during extraction, 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) and the original exception will
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* be rethrown if badbit is set in the exceptions mask.
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*/
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/**
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* @brief Simple extraction.
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* @return A character, or eof().
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*
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* Tries to extract a character. If none are available, sets failbit
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* and returns traits::eof().
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*/
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int_type
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get();
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/**
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* @brief Simple extraction.
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* @param __c The character in which to store data.
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* @return *this
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*
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* Tries to extract a character and store it in @a __c. If none are
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* available, sets failbit and returns traits::eof().
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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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__istream_type&
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get(char_type& __c);
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/**
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* @brief Simple multiple-character extraction.
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* @param __s Pointer to an array.
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* @param __n Maximum number of characters to store in @a __s.
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* @param __delim A "stop" character.
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* @return *this
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*
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* Characters are extracted and stored into @a __s until one of the
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* following happens:
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*
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* - @c __n-1 characters are stored
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* - the input sequence reaches EOF
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* - the next character equals @a __delim, in which case the character
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* is not extracted
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*
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* If no characters are stored, failbit is set in the stream's error
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* state.
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*
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* In any case, a null character is stored into the next location in
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* the array.
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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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__istream_type&
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get(char_type* __s, streamsize __n, char_type __delim);
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/**
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* @brief Simple multiple-character extraction.
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* @param __s Pointer to an array.
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* @param __n Maximum number of characters to store in @a s.
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* @return *this
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*
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* Returns @c get(__s,__n,widen('\\n')).
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*/
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__istream_type&
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get(char_type* __s, streamsize __n)
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{ return this->get(__s, __n, this->widen('\n')); }
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/**
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* @brief Extraction into another streambuf.
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* @param __sb A streambuf in which to store data.
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* @param __delim A "stop" character.
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* @return *this
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*
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* Characters are extracted and inserted into @a __sb until one of the
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* following happens:
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*
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* - the input sequence reaches EOF
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* - insertion into the output buffer fails (in this case, the
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* character that would have been inserted is not extracted)
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* - the next character equals @a __delim (in this case, the character
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* is not extracted)
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* - an exception occurs (and in this case is caught)
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*
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* If no characters are stored, failbit is set in the stream's error
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* state.
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*/
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__istream_type&
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get(__streambuf_type& __sb, char_type __delim);
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/**
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* @brief Extraction into another streambuf.
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* @param __sb A streambuf in which to store data.
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* @return *this
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*
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* Returns @c get(__sb,widen('\\n')).
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*/
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__istream_type&
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get(__streambuf_type& __sb)
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{ return this->get(__sb, this->widen('\n')); }
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/**
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* @brief String extraction.
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* @param __s A character array in which to store the data.
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* @param __n Maximum number of characters to extract.
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* @param __delim A "stop" character.
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* @return *this
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*
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* Extracts and stores characters into @a __s until one of the
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* following happens. Note that these criteria are required to be
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* tested in the order listed here, to allow an input line to exactly
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* fill the @a __s array without setting failbit.
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*
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* -# the input sequence reaches end-of-file, in which case eofbit
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* is set in the stream error state
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* -# the next character equals @c __delim, in which case the character
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* is extracted (and therefore counted in @c gcount()) but not stored
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* -# @c __n-1 characters are stored, in which case failbit is set
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* in the stream error state
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*
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* If no characters are extracted, failbit is set. (An empty line of
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* input should therefore not cause failbit to be set.)
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*
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* In any case, a null character is stored in the next location in
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* the array.
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*/
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__istream_type&
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getline(char_type* __s, streamsize __n, char_type __delim);
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/**
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* @brief String extraction.
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* @param __s A character array in which to store the data.
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* @param __n Maximum number of characters to extract.
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* @return *this
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*
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* Returns @c getline(__s,__n,widen('\\n')).
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*/
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__istream_type&
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getline(char_type* __s, streamsize __n)
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{ return this->getline(__s, __n, this->widen('\n')); }
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/**
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* @brief Discarding characters
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* @param __n Number of characters to discard.
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* @param __delim A "stop" character.
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* @return *this
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*
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* Extracts characters and throws them away until one of the
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* following happens:
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* - if @a __n @c != @c std::numeric_limits<int>::max(), @a __n
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* characters are extracted
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* - the input sequence reaches end-of-file
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* - the next character equals @a __delim (in this case, the character
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* is extracted); note that this condition will never occur if
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* @a __delim equals @c traits::eof().
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*
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* NB: Provide three overloads, instead of the single function
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* (with defaults) mandated by the Standard: this leads to a
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* better performing implementation, while still conforming to
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* the Standard.
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*/
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__istream_type&
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ignore(streamsize __n, int_type __delim);
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__istream_type&
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ignore(streamsize __n);
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__istream_type&
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ignore();
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/**
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* @brief Looking ahead in the stream
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* @return The next character, or eof().
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*
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* If, after constructing the sentry object, @c good() is false,
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* returns @c traits::eof(). Otherwise reads but does not extract
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* the next input character.
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*/
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int_type
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peek();
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/**
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* @brief Extraction without delimiters.
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* @param __s A character array.
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* @param __n Maximum number of characters to store.
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* @return *this
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*
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* If the stream state is @c good(), extracts characters and stores
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* them into @a __s until one of the following happens:
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* - @a __n characters are stored
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* - the input sequence reaches end-of-file, in which case the error
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* state is set to @c failbit|eofbit.
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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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__istream_type&
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read(char_type* __s, streamsize __n);
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/**
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* @brief Extraction until the buffer is exhausted, but no more.
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* @param __s A character array.
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* @param __n Maximum number of characters to store.
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* @return The number of characters extracted.
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*
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* Extracts characters and stores them into @a __s depending on the
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* number of characters remaining in the streambuf's buffer,
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* @c rdbuf()->in_avail(), called @c A here:
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* - if @c A @c == @c -1, sets eofbit and extracts no characters
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* - if @c A @c == @c 0, extracts no characters
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* - if @c A @c > @c 0, extracts @c min(A,n)
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*
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* The goal is to empty the current buffer, and to not request any
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* more from the external input sequence controlled by the streambuf.
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*/
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streamsize
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readsome(char_type* __s, streamsize __n);
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/**
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* @brief Unextracting a single character.
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* @param __c The character to push back into the input stream.
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* @return *this
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*
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* If @c rdbuf() is not null, calls @c rdbuf()->sputbackc(c).
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*
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* If @c rdbuf() is null or if @c sputbackc() fails, sets badbit in
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* the error state.
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*
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* @note This function first clears eofbit. Since no characters
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* are extracted, the next call to @c gcount() will return 0,
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* as required by DR 60.
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*/
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__istream_type&
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putback(char_type __c);
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/**
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* @brief Unextracting the previous character.
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* @return *this
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*
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* If @c rdbuf() is not null, calls @c rdbuf()->sungetc(c).
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*
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* If @c rdbuf() is null or if @c sungetc() fails, sets badbit in
|
|
* the error state.
|
|
*
|
|
* @note This function first clears eofbit. Since no characters
|
|
* are extracted, the next call to @c gcount() will return 0,
|
|
* as required by DR 60.
|
|
*/
|
|
__istream_type&
|
|
unget();
|
|
|
|
/**
|
|
* @brief Synchronizing the stream buffer.
|
|
* @return 0 on success, -1 on failure
|
|
*
|
|
* If @c rdbuf() is a null pointer, returns -1.
|
|
*
|
|
* Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
|
|
* sets badbit and returns -1.
|
|
*
|
|
* Otherwise, returns 0.
|
|
*
|
|
* @note This function does not count the number of characters
|
|
* extracted, if any, and therefore does not affect the next
|
|
* call to @c gcount().
|
|
*/
|
|
int
|
|
sync();
|
|
|
|
/**
|
|
* @brief Getting the current read position.
|
|
* @return A file position object.
|
|
*
|
|
* If @c fail() is not false, returns @c pos_type(-1) to indicate
|
|
* failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,in).
|
|
*
|
|
* @note This function does not count the number of characters
|
|
* extracted, if any, and therefore does not affect the next
|
|
* call to @c gcount(). At variance with putback, unget and
|
|
* seekg, eofbit is not cleared first.
|
|
*/
|
|
pos_type
|
|
tellg();
|
|
|
|
/**
|
|
* @brief Changing the current read position.
|
|
* @param __pos A file position object.
|
|
* @return *this
|
|
*
|
|
* If @c fail() is not true, calls @c rdbuf()->pubseekpos(__pos). If
|
|
* that function fails, sets failbit.
|
|
*
|
|
* @note This function first clears eofbit. It does not count the
|
|
* number of characters extracted, if any, and therefore does
|
|
* not affect the next call to @c gcount().
|
|
*/
|
|
__istream_type&
|
|
seekg(pos_type);
|
|
|
|
/**
|
|
* @brief Changing the current read position.
|
|
* @param __off A file offset object.
|
|
* @param __dir The direction in which to seek.
|
|
* @return *this
|
|
*
|
|
* If @c fail() is not true, calls @c rdbuf()->pubseekoff(__off,__dir).
|
|
* If that function fails, sets failbit.
|
|
*
|
|
* @note This function first clears eofbit. It does not count the
|
|
* number of characters extracted, if any, and therefore does
|
|
* not affect the next call to @c gcount().
|
|
*/
|
|
__istream_type&
|
|
seekg(off_type, ios_base::seekdir);
|
|
///@}
|
|
|
|
protected:
|
|
basic_istream()
|
|
: _M_gcount(streamsize(0))
|
|
{ this->init(0); }
|
|
|
|
#if __cplusplus >= 201103L
|
|
basic_istream(const basic_istream&) = delete;
|
|
|
|
basic_istream(basic_istream&& __rhs)
|
|
: __ios_type(), _M_gcount(__rhs._M_gcount)
|
|
{
|
|
__ios_type::move(__rhs);
|
|
__rhs._M_gcount = 0;
|
|
}
|
|
|
|
// 27.7.3.3 Assign/swap
|
|
|
|
basic_istream& operator=(const basic_istream&) = delete;
|
|
|
|
basic_istream&
|
|
operator=(basic_istream&& __rhs)
|
|
{
|
|
swap(__rhs);
|
|
return *this;
|
|
}
|
|
|
|
void
|
|
swap(basic_istream& __rhs)
|
|
{
|
|
__ios_type::swap(__rhs);
|
|
std::swap(_M_gcount, __rhs._M_gcount);
|
|
}
|
|
#endif
|
|
|
|
template<typename _ValueT>
|
|
__istream_type&
|
|
_M_extract(_ValueT& __v);
|
|
};
|
|
|
|
/// Explicit specialization declarations, defined in src/istream.cc.
|
|
template<>
|
|
basic_istream<char>&
|
|
basic_istream<char>::
|
|
getline(char_type* __s, streamsize __n, char_type __delim);
|
|
|
|
template<>
|
|
basic_istream<char>&
|
|
basic_istream<char>::
|
|
ignore(streamsize __n);
|
|
|
|
template<>
|
|
basic_istream<char>&
|
|
basic_istream<char>::
|
|
ignore(streamsize __n, int_type __delim);
|
|
|
|
#ifdef _GLIBCXX_USE_WCHAR_T
|
|
template<>
|
|
basic_istream<wchar_t>&
|
|
basic_istream<wchar_t>::
|
|
getline(char_type* __s, streamsize __n, char_type __delim);
|
|
|
|
template<>
|
|
basic_istream<wchar_t>&
|
|
basic_istream<wchar_t>::
|
|
ignore(streamsize __n);
|
|
|
|
template<>
|
|
basic_istream<wchar_t>&
|
|
basic_istream<wchar_t>::
|
|
ignore(streamsize __n, int_type __delim);
|
|
#endif
|
|
|
|
/**
|
|
* @brief Performs setup work for input streams.
|
|
*
|
|
* Objects of this class are created before all of the standard
|
|
* extractors are run. It is responsible for <em>exception-safe
|
|
* prefix and suffix operations,</em> although only prefix actions
|
|
* are currently required by the standard.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
class basic_istream<_CharT, _Traits>::sentry
|
|
{
|
|
// Data Members.
|
|
bool _M_ok;
|
|
|
|
public:
|
|
/// Easy access to dependent types.
|
|
typedef _Traits traits_type;
|
|
typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
|
|
typedef basic_istream<_CharT, _Traits> __istream_type;
|
|
typedef typename __istream_type::__ctype_type __ctype_type;
|
|
typedef typename _Traits::int_type __int_type;
|
|
|
|
/**
|
|
* @brief The constructor performs all the work.
|
|
* @param __is The input stream to guard.
|
|
* @param __noskipws Whether to consume whitespace or not.
|
|
*
|
|
* If the stream state is good (@a __is.good() is true), then the
|
|
* following actions are performed, otherwise the sentry state
|
|
* is false (<em>not okay</em>) and failbit is set in the
|
|
* stream state.
|
|
*
|
|
* The sentry's preparatory actions are:
|
|
*
|
|
* -# if the stream is tied to an output stream, @c is.tie()->flush()
|
|
* is called to synchronize the output sequence
|
|
* -# if @a __noskipws is false, and @c ios_base::skipws is set in
|
|
* @c is.flags(), the sentry extracts and discards whitespace
|
|
* characters from the stream. The currently imbued locale is
|
|
* used to determine whether each character is whitespace.
|
|
*
|
|
* If the stream state is still good, then the sentry state becomes
|
|
* true (@a okay).
|
|
*/
|
|
explicit
|
|
sentry(basic_istream<_CharT, _Traits>& __is, bool __noskipws = false);
|
|
|
|
/**
|
|
* @brief Quick status checking.
|
|
* @return The sentry state.
|
|
*
|
|
* For ease of use, sentries may be converted to booleans. The
|
|
* return value is that of the sentry state (true == okay).
|
|
*/
|
|
#if __cplusplus >= 201103L
|
|
explicit
|
|
#endif
|
|
operator bool() const
|
|
{ return _M_ok; }
|
|
};
|
|
|
|
///@{
|
|
/**
|
|
* @brief Character extractors
|
|
* @param __in An input stream.
|
|
* @param __c A character reference.
|
|
* @return in
|
|
*
|
|
* Behaves like one of the formatted arithmetic extractors described in
|
|
* std::basic_istream. After constructing a sentry object with good
|
|
* status, this function extracts a character (if one is available) and
|
|
* stores it in @a __c. Otherwise, sets failbit in the input stream.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c);
|
|
|
|
template<class _Traits>
|
|
inline basic_istream<char, _Traits>&
|
|
operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c)
|
|
{ return (__in >> reinterpret_cast<char&>(__c)); }
|
|
|
|
template<class _Traits>
|
|
inline basic_istream<char, _Traits>&
|
|
operator>>(basic_istream<char, _Traits>& __in, signed char& __c)
|
|
{ return (__in >> reinterpret_cast<char&>(__c)); }
|
|
///@}
|
|
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
void
|
|
__istream_extract(basic_istream<_CharT, _Traits>&, _CharT*, streamsize);
|
|
|
|
void __istream_extract(istream&, char*, streamsize);
|
|
|
|
///@{
|
|
/**
|
|
* @brief Character string extractors
|
|
* @param __in An input stream.
|
|
* @param __s A character array (or a pointer to an array before C++20).
|
|
* @return __in
|
|
*
|
|
* Behaves like one of the formatted arithmetic extractors described in
|
|
* `std::basic_istream`. After constructing a sentry object with good
|
|
* status, this function extracts up to `n` characters and stores them
|
|
* into the array `__s`. `n` is defined as:
|
|
*
|
|
* - if `width()` is greater than zero, `n` is `min(width(), n)`
|
|
* - otherwise `n` is the number of elements of the array
|
|
* - (before C++20 the pointer is assumed to point to an array of
|
|
* - the largest possible size for an array of `char_type`).
|
|
*
|
|
* Characters are extracted and stored until one of the following happens:
|
|
* - `n - 1` characters are stored
|
|
* - EOF is reached
|
|
* - the next character is whitespace according to the current locale
|
|
*
|
|
* `width(0)` is then called for the input stream.
|
|
*
|
|
* If no characters are extracted, sets failbit.
|
|
*/
|
|
|
|
#if __cplusplus <= 201703L
|
|
template<typename _CharT, typename _Traits>
|
|
__attribute__((__nonnull__(2), __access__(__write_only__, 2)))
|
|
inline basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
|
|
{
|
|
size_t __n = __builtin_object_size(__s, 0);
|
|
if (__builtin_expect(__n < sizeof(_CharT), false))
|
|
{
|
|
// There is not even space for the required null terminator.
|
|
__glibcxx_assert(__n >= sizeof(_CharT));
|
|
__in.width(0);
|
|
__in.setstate(ios_base::failbit);
|
|
}
|
|
else
|
|
{
|
|
if (__n == (size_t)-1)
|
|
__n = __gnu_cxx::__numeric_traits<streamsize>::__max;
|
|
std::__istream_extract(__in, __s, __n / sizeof(_CharT));
|
|
}
|
|
return __in;
|
|
}
|
|
|
|
template<class _Traits>
|
|
__attribute__((__nonnull__(2), __access__(__write_only__, 2)))
|
|
inline basic_istream<char, _Traits>&
|
|
operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s)
|
|
{ return __in >> reinterpret_cast<char*>(__s); }
|
|
|
|
template<class _Traits>
|
|
__attribute__((__nonnull__(2), __access__(__write_only__, 2)))
|
|
inline basic_istream<char, _Traits>&
|
|
operator>>(basic_istream<char, _Traits>& __in, signed char* __s)
|
|
{ return __in >> reinterpret_cast<char*>(__s); }
|
|
#else
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 2499. operator>>(istream&, char*) makes it hard to avoid buffer overflows
|
|
template<typename _CharT, typename _Traits, size_t _Num>
|
|
inline basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __in, _CharT (&__s)[_Num])
|
|
{
|
|
static_assert(_Num <= __gnu_cxx::__numeric_traits<streamsize>::__max);
|
|
std::__istream_extract(__in, __s, _Num);
|
|
return __in;
|
|
}
|
|
|
|
template<class _Traits, size_t _Num>
|
|
inline basic_istream<char, _Traits>&
|
|
operator>>(basic_istream<char, _Traits>& __in, unsigned char (&__s)[_Num])
|
|
{ return __in >> reinterpret_cast<char(&)[_Num]>(__s); }
|
|
|
|
template<class _Traits, size_t _Num>
|
|
inline basic_istream<char, _Traits>&
|
|
operator>>(basic_istream<char, _Traits>& __in, signed char (&__s)[_Num])
|
|
{ return __in >> reinterpret_cast<char(&)[_Num]>(__s); }
|
|
#endif
|
|
///@}
|
|
|
|
/**
|
|
* @brief Template class basic_iostream
|
|
* @ingroup io
|
|
*
|
|
* @tparam _CharT Type of character stream.
|
|
* @tparam _Traits Traits for character type, defaults to
|
|
* char_traits<_CharT>.
|
|
*
|
|
* This class multiply inherits from the input and output stream classes
|
|
* simply to provide a single interface.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
class basic_iostream
|
|
: public basic_istream<_CharT, _Traits>,
|
|
public basic_ostream<_CharT, _Traits>
|
|
{
|
|
public:
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 271. basic_iostream missing typedefs
|
|
// Types (inherited):
|
|
typedef _CharT char_type;
|
|
typedef typename _Traits::int_type int_type;
|
|
typedef typename _Traits::pos_type pos_type;
|
|
typedef typename _Traits::off_type off_type;
|
|
typedef _Traits traits_type;
|
|
|
|
// Non-standard Types:
|
|
typedef basic_istream<_CharT, _Traits> __istream_type;
|
|
typedef basic_ostream<_CharT, _Traits> __ostream_type;
|
|
|
|
/**
|
|
* @brief Constructor does nothing.
|
|
*
|
|
* Both of the parent classes are initialized with the same
|
|
* streambuf pointer passed to this constructor.
|
|
*/
|
|
explicit
|
|
basic_iostream(basic_streambuf<_CharT, _Traits>* __sb)
|
|
: __istream_type(__sb), __ostream_type(__sb) { }
|
|
|
|
/**
|
|
* @brief Destructor does nothing.
|
|
*/
|
|
virtual
|
|
~basic_iostream() { }
|
|
|
|
protected:
|
|
basic_iostream()
|
|
: __istream_type(), __ostream_type() { }
|
|
|
|
#if __cplusplus >= 201103L
|
|
basic_iostream(const basic_iostream&) = delete;
|
|
|
|
basic_iostream(basic_iostream&& __rhs)
|
|
: __istream_type(std::move(__rhs)), __ostream_type(*this)
|
|
{ }
|
|
|
|
// 27.7.3.3 Assign/swap
|
|
|
|
basic_iostream& operator=(const basic_iostream&) = delete;
|
|
|
|
basic_iostream&
|
|
operator=(basic_iostream&& __rhs)
|
|
{
|
|
swap(__rhs);
|
|
return *this;
|
|
}
|
|
|
|
void
|
|
swap(basic_iostream& __rhs)
|
|
{ __istream_type::swap(__rhs); }
|
|
#endif
|
|
};
|
|
|
|
/**
|
|
* @brief Quick and easy way to eat whitespace
|
|
*
|
|
* This manipulator extracts whitespace characters, stopping when the
|
|
* next character is non-whitespace, or when the input sequence is empty.
|
|
* If the sequence is empty, @c eofbit is set in the stream, but not
|
|
* @c failbit.
|
|
*
|
|
* The current locale is used to distinguish whitespace characters.
|
|
*
|
|
* Example:
|
|
* @code
|
|
* MyClass mc;
|
|
*
|
|
* std::cin >> std::ws >> mc;
|
|
* @endcode
|
|
* will skip leading whitespace before calling operator>> on cin and your
|
|
* object. Note that the same effect can be achieved by creating a
|
|
* std::basic_istream::sentry inside your definition of operator>>.
|
|
*/
|
|
template<typename _CharT, typename _Traits>
|
|
basic_istream<_CharT, _Traits>&
|
|
ws(basic_istream<_CharT, _Traits>& __is);
|
|
|
|
#if __cplusplus >= 201103L
|
|
// C++11 27.7.2.6 Rvalue stream extraction [istream.rvalue]
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 2328. Rvalue stream extraction should use perfect forwarding
|
|
// 1203. More useful rvalue stream insertion
|
|
|
|
#if __cpp_lib_concepts
|
|
template<typename _Is, typename _Tp>
|
|
requires __derived_from_ios_base<_Is>
|
|
&& requires (_Is& __is, _Tp&& __t) { __is >> std::forward<_Tp>(__t); }
|
|
using __rvalue_stream_extraction_t = _Is&&;
|
|
#else
|
|
template<typename _Is, typename _Tp,
|
|
typename = _Require_derived_from_ios_base<_Is>,
|
|
typename = decltype(std::declval<_Is&>() >> std::declval<_Tp>())>
|
|
using __rvalue_stream_extraction_t = _Is&&;
|
|
#endif
|
|
|
|
/**
|
|
* @brief Generic extractor for rvalue stream
|
|
* @param __is An input stream.
|
|
* @param __x A reference to the extraction target.
|
|
* @return __is
|
|
*
|
|
* This is just a forwarding function to allow extraction from
|
|
* rvalue streams since they won't bind to the extractor functions
|
|
* that take an lvalue reference.
|
|
*/
|
|
template<typename _Istream, typename _Tp>
|
|
inline __rvalue_stream_extraction_t<_Istream, _Tp>
|
|
operator>>(_Istream&& __is, _Tp&& __x)
|
|
{
|
|
__is >> std::forward<_Tp>(__x);
|
|
return std::move(__is);
|
|
}
|
|
#endif // C++11
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace
|
|
|
|
#include <bits/istream.tcc>
|
|
|
|
#endif /* _GLIBCXX_ISTREAM */
|