| // Input streams -*- C++ -*- |
| |
| // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, |
| // 2006, 2007, 2008, 2009, 2010, 2011 |
| // Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| // |
| // ISO C++ 14882: 27.6.1 Input streams |
| // |
| |
| /** @file include/istream |
| * This is a Standard C++ Library header. |
| */ |
| |
| #ifndef _GLIBCXX_ISTREAM |
| #define _GLIBCXX_ISTREAM 1 |
| |
| #pragma GCC system_header |
| |
| #include <ios> |
| #include <ostream> |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| // [27.6.1.1] Template class basic_istream |
| /** |
| * @brief Controlling input. |
| * @ingroup io |
| * |
| * This is the base class for all input streams. It provides text |
| * formatting of all builtin types, and communicates with any class |
| * derived from basic_streambuf to do the actual input. |
| */ |
| template<typename _CharT, typename _Traits> |
| class basic_istream : virtual public basic_ios<_CharT, _Traits> |
| { |
| public: |
| // Types (inherited from basic_ios (27.4.4)): |
| 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_streambuf<_CharT, _Traits> __streambuf_type; |
| typedef basic_ios<_CharT, _Traits> __ios_type; |
| typedef basic_istream<_CharT, _Traits> __istream_type; |
| typedef num_get<_CharT, istreambuf_iterator<_CharT, _Traits> > |
| __num_get_type; |
| typedef ctype<_CharT> __ctype_type; |
| |
| protected: |
| // Data Members: |
| /** |
| * The number of characters extracted in the previous unformatted |
| * function; see gcount(). |
| */ |
| streamsize _M_gcount; |
| |
| public: |
| // [27.6.1.1.1] constructor/destructor |
| /** |
| * @brief Base constructor. |
| * |
| * This ctor is almost never called by the user directly, rather from |
| * derived classes' initialization lists, which pass a pointer to |
| * their own stream buffer. |
| */ |
| explicit |
| basic_istream(__streambuf_type* __sb) |
| : _M_gcount(streamsize(0)) |
| { this->init(__sb); } |
| |
| /** |
| * @brief Base destructor. |
| * |
| * This does very little apart from providing a virtual base dtor. |
| */ |
| virtual |
| ~basic_istream() |
| { _M_gcount = streamsize(0); } |
| |
| // [27.6.1.1.2] prefix/suffix |
| class sentry; |
| friend class sentry; |
| |
| // [27.6.1.2] formatted input |
| // [27.6.1.2.3] basic_istream::operator>> |
| //@{ |
| /** |
| * @brief Interface for manipulators. |
| * |
| * Manipulators such as @c std::ws and @c std::dec use these |
| * functions in constructs like |
| * <code>std::cin >> std::ws</code>. |
| * For more information, see the iomanip header. |
| */ |
| __istream_type& |
| operator>>(__istream_type& (*__pf)(__istream_type&)) |
| { return __pf(*this); } |
| |
| __istream_type& |
| operator>>(__ios_type& (*__pf)(__ios_type&)) |
| { |
| __pf(*this); |
| return *this; |
| } |
| |
| __istream_type& |
| operator>>(ios_base& (*__pf)(ios_base&)) |
| { |
| __pf(*this); |
| return *this; |
| } |
| //@} |
| |
| // [27.6.1.2.2] arithmetic extractors |
| /** |
| * @name Arithmetic Extractors |
| * |
| * All the @c operator>> functions (aka <em>formatted input |
| * functions</em>) have some common behavior. Each starts by |
| * constructing a temporary object of type std::basic_istream::sentry |
| * with the second argument (noskipws) set to false. This has several |
| * effects, concluding with the setting of a status flag; see the |
| * sentry documentation for more. |
| * |
| * If the sentry status is good, the function tries to extract |
| * whatever data is appropriate for the type of the argument. |
| * |
| * If an exception is thrown during extraction, ios_base::badbit |
| * will be turned on in the stream's error state without causing an |
| * ios_base::failure to be thrown. The original exception will then |
| * be rethrown. |
| */ |
| //@{ |
| /** |
| * @brief Basic arithmetic extractors |
| * @param A variable of builtin type. |
| * @return @c *this if successful |
| * |
| * These functions use the stream's current locale (specifically, the |
| * @c num_get facet) to parse the input data. |
| */ |
| __istream_type& |
| operator>>(bool& __n) |
| { return _M_extract(__n); } |
| |
| __istream_type& |
| operator>>(short& __n); |
| |
| __istream_type& |
| operator>>(unsigned short& __n) |
| { return _M_extract(__n); } |
| |
| __istream_type& |
| operator>>(int& __n); |
| |
| __istream_type& |
| operator>>(unsigned int& __n) |
| { return _M_extract(__n); } |
| |
| __istream_type& |
| operator>>(long& __n) |
| { return _M_extract(__n); } |
| |
| __istream_type& |
| operator>>(unsigned long& __n) |
| { return _M_extract(__n); } |
| |
| #ifdef _GLIBCXX_USE_LONG_LONG |
| __istream_type& |
| operator>>(long long& __n) |
| { return _M_extract(__n); } |
| |
| __istream_type& |
| operator>>(unsigned long long& __n) |
| { return _M_extract(__n); } |
| #endif |
| |
| __istream_type& |
| operator>>(float& __f) |
| { return _M_extract(__f); } |
| |
| __istream_type& |
| operator>>(double& __f) |
| { return _M_extract(__f); } |
| |
| __istream_type& |
| operator>>(long double& __f) |
| { return _M_extract(__f); } |
| |
| __istream_type& |
| operator>>(void*& __p) |
| { return _M_extract(__p); } |
| |
| /** |
| * @brief Extracting into another streambuf. |
| * @param sb A pointer to a streambuf |
| * |
| * This function behaves like one of the basic arithmetic extractors, |
| * in that it also constructs a sentry object and has the same error |
| * handling behavior. |
| * |
| * If @a sb is NULL, the stream will set failbit in its error state. |
| * |
| * Characters are extracted from this stream and inserted into the |
| * @a sb streambuf until one of the following occurs: |
| * |
| * - the input stream reaches end-of-file, |
| * - insertion into the output buffer fails (in this case, the |
| * character that would have been inserted is not extracted), or |
| * - an exception occurs (and in this case is caught) |
| * |
| * If the function inserts no characters, failbit is set. |
| */ |
| __istream_type& |
| operator>>(__streambuf_type* __sb); |
| //@} |
| |
| // [27.6.1.3] unformatted input |
| /** |
| * @brief Character counting |
| * @return The number of characters extracted by the previous |
| * unformatted input function dispatched for this stream. |
| */ |
| streamsize |
| gcount() const |
| { return _M_gcount; } |
| |
| /** |
| * @name Unformatted Input Functions |
| * |
| * All the unformatted input functions have some common behavior. |
| * Each starts by constructing a temporary object of type |
| * std::basic_istream::sentry with the second argument (noskipws) |
| * set to true. This has several effects, concluding with the |
| * setting of a status flag; see the sentry documentation for more. |
| * |
| * If the sentry status is good, the function tries to extract |
| * whatever data is appropriate for the type of the argument. |
| * |
| * The number of characters extracted is stored for later retrieval |
| * by gcount(). |
| * |
| * If an exception is thrown during extraction, ios_base::badbit |
| * will be turned on in the stream's error state without causing an |
| * ios_base::failure to be thrown. The original exception will then |
| * be rethrown. |
| */ |
| //@{ |
| /** |
| * @brief Simple extraction. |
| * @return A character, or eof(). |
| * |
| * Tries to extract a character. If none are available, sets failbit |
| * and returns traits::eof(). |
| */ |
| int_type |
| get(); |
| |
| /** |
| * @brief Simple extraction. |
| * @param c The character in which to store data. |
| * @return *this |
| * |
| * Tries to extract a character and store it in @a c. If none are |
| * available, sets failbit and returns traits::eof(). |
| * |
| * @note This function is not overloaded on signed char and |
| * unsigned char. |
| */ |
| __istream_type& |
| get(char_type& __c); |
| |
| /** |
| * @brief Simple multiple-character extraction. |
| * @param s Pointer to an array. |
| * @param n Maximum number of characters to store in @a s. |
| * @param delim A "stop" character. |
| * @return *this |
| * |
| * Characters are extracted and stored into @a s until one of the |
| * following happens: |
| * |
| * - @c n-1 characters are stored |
| * - the input sequence reaches EOF |
| * - the next character equals @a delim, in which case the character |
| * is not extracted |
| * |
| * If no characters are stored, failbit is set in the stream's error |
| * state. |
| * |
| * In any case, a null character is stored into the next location in |
| * the array. |
| * |
| * @note This function is not overloaded on signed char and |
| * unsigned char. |
| */ |
| __istream_type& |
| get(char_type* __s, streamsize __n, char_type __delim); |
| |
| /** |
| * @brief Simple multiple-character extraction. |
| * @param s Pointer to an array. |
| * @param n Maximum number of characters to store in @a s. |
| * @return *this |
| * |
| * Returns @c get(s,n,widen('\\n')). |
| */ |
| __istream_type& |
| get(char_type* __s, streamsize __n) |
| { return this->get(__s, __n, this->widen('\n')); } |
| |
| /** |
| * @brief Extraction into another streambuf. |
| * @param sb A streambuf in which to store data. |
| * @param delim A "stop" character. |
| * @return *this |
| * |
| * Characters are extracted and inserted into @a sb until one of the |
| * following happens: |
| * |
| * - the input sequence reaches EOF |
| * - insertion into the output buffer fails (in this case, the |
| * character that would have been inserted is not extracted) |
| * - the next character equals @a delim (in this case, the character |
| * is not extracted) |
| * - an exception occurs (and in this case is caught) |
| * |
| * If no characters are stored, failbit is set in the stream's error |
| * state. |
| */ |
| __istream_type& |
| get(__streambuf_type& __sb, char_type __delim); |
| |
| /** |
| * @brief Extraction into another streambuf. |
| * @param sb A streambuf in which to store data. |
| * @return *this |
| * |
| * Returns @c get(sb,widen('\\n')). |
| */ |
| __istream_type& |
| get(__streambuf_type& __sb) |
| { return this->get(__sb, this->widen('\n')); } |
| |
| /** |
| * @brief String extraction. |
| * @param s A character array in which to store the data. |
| * @param n Maximum number of characters to extract. |
| * @param delim A "stop" character. |
| * @return *this |
| * |
| * Extracts and stores characters into @a s until one of the |
| * following happens. Note that these criteria are required to be |
| * tested in the order listed here, to allow an input line to exactly |
| * fill the @a s array without setting failbit. |
| * |
| * -# the input sequence reaches end-of-file, in which case eofbit |
| * is set in the stream error state |
| * -# the next character equals @c delim, in which case the character |
| * is extracted (and therefore counted in @c gcount()) but not stored |
| * -# @c n-1 characters are stored, in which case failbit is set |
| * in the stream error state |
| * |
| * If no characters are extracted, failbit is set. (An empty line of |
| * input should therefore not cause failbit to be set.) |
| * |
| * In any case, a null character is stored in the next location in |
| * the array. |
| */ |
| __istream_type& |
| getline(char_type* __s, streamsize __n, char_type __delim); |
| |
| /** |
| * @brief String extraction. |
| * @param s A character array in which to store the data. |
| * @param n Maximum number of characters to extract. |
| * @return *this |
| * |
| * Returns @c getline(s,n,widen('\\n')). |
| */ |
| __istream_type& |
| getline(char_type* __s, streamsize __n) |
| { return this->getline(__s, __n, this->widen('\n')); } |
| |
| /** |
| * @brief Discarding characters |
| * @param n Number of characters to discard. |
| * @param delim A "stop" character. |
| * @return *this |
| * |
| * Extracts characters and throws them away until one of the |
| * following happens: |
| * - if @a n @c != @c std::numeric_limits<int>::max(), @a n |
| * characters are extracted |
| * - the input sequence reaches end-of-file |
| * - the next character equals @a delim (in this case, the character |
| * is extracted); note that this condition will never occur if |
| * @a delim equals @c traits::eof(). |
| * |
| * NB: Provide three overloads, instead of the single function |
| * (with defaults) mandated by the Standard: this leads to a |
| * better performing implementation, while still conforming to |
| * the Standard. |
| */ |
| __istream_type& |
| ignore(); |
| |
| __istream_type& |
| ignore(streamsize __n); |
| |
| __istream_type& |
| ignore(streamsize __n, int_type __delim); |
| |
| /** |
| * @brief Looking ahead in the stream |
| * @return The next character, or eof(). |
| * |
| * If, after constructing the sentry object, @c good() is false, |
| * returns @c traits::eof(). Otherwise reads but does not extract |
| * the next input character. |
| */ |
| int_type |
| peek(); |
| |
| /** |
| * @brief Extraction without delimiters. |
| * @param s A character array. |
| * @param n Maximum number of characters to store. |
| * @return *this |
| * |
| * If the stream state is @c good(), extracts characters and stores |
| * them into @a s until one of the following happens: |
| * - @a n characters are stored |
| * - the input sequence reaches end-of-file, in which case the error |
| * state is set to @c failbit|eofbit. |
| * |
| * @note This function is not overloaded on signed char and |
| * unsigned char. |
| */ |
| __istream_type& |
| read(char_type* __s, streamsize __n); |
| |
| /** |
| * @brief Extraction until the buffer is exhausted, but no more. |
| * @param s A character array. |
| * @param n Maximum number of characters to store. |
| * @return The number of characters extracted. |
| * |
| * Extracts characters and stores them into @a s depending on the |
| * number of characters remaining in the streambuf's buffer, |
| * @c rdbuf()->in_avail(), called @c A here: |
| * - if @c A @c == @c -1, sets eofbit and extracts no characters |
| * - if @c A @c == @c 0, extracts no characters |
| * - if @c A @c > @c 0, extracts @c min(A,n) |
| * |
| * The goal is to empty the current buffer, and to not request any |
| * more from the external input sequence controlled by the streambuf. |
| */ |
| streamsize |
| readsome(char_type* __s, streamsize __n); |
| |
| /** |
| * @brief Unextracting a single character. |
| * @param c The character to push back into the input stream. |
| * @return *this |
| * |
| * If @c rdbuf() is not null, calls @c rdbuf()->sputbackc(c). |
| * |
| * If @c rdbuf() is null or if @c sputbackc() 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& |
| putback(char_type __c); |
| |
| /** |
| * @brief Unextracting the previous character. |
| * @return *this |
| * |
| * If @c rdbuf() is not null, calls @c rdbuf()->sungetc(c). |
| * |
| * 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); } |
| |
| 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 dependant 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). |
| */ |
| #ifdef __GXX_EXPERIMENTAL_CXX0X__ |
| explicit |
| #endif |
| operator bool() const |
| { return _M_ok; } |
| }; |
| |
| // [27.6.1.2.3] character extraction templates |
| //@{ |
| /** |
| * @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)); } |
| //@} |
| |
| //@{ |
| /** |
| * @brief Character string extractors |
| * @param in An input stream. |
| * @param s A pointer to a character array. |
| * @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 @c n characters and stores them |
| * into the array starting at @a s. @c n is defined as: |
| * |
| * - if @c width() is greater than zero, @c n is width() otherwise |
| * - @c n is <em>the number of elements of the largest array of * |
| * - @c char_type that can store a terminating @c eos.</em> |
| * - [27.6.1.2.3]/6 |
| * |
| * Characters are extracted and stored until one of the following happens: |
| * - @c n-1 characters are stored |
| * - EOF is reached |
| * - the next character is whitespace according to the current locale |
| * - the next character is a null byte (i.e., @c charT() ) |
| * |
| * @c width(0) is then called for the input stream. |
| * |
| * If no characters are extracted, sets failbit. |
| */ |
| template<typename _CharT, typename _Traits> |
| basic_istream<_CharT, _Traits>& |
| operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s); |
| |
| // Explicit specialization declaration, defined in src/istream.cc. |
| template<> |
| basic_istream<char>& |
| operator>>(basic_istream<char>& __in, char* __s); |
| |
| template<class _Traits> |
| inline basic_istream<char, _Traits>& |
| operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s) |
| { return (__in >> reinterpret_cast<char*>(__s)); } |
| |
| template<class _Traits> |
| inline basic_istream<char, _Traits>& |
| operator>>(basic_istream<char, _Traits>& __in, signed char* __s) |
| { return (__in >> reinterpret_cast<char*>(__s)); } |
| //@} |
| |
| // 27.6.1.5 Template class basic_iostream |
| /** |
| * @brief Merging istream and ostream capabilities. |
| * @ingroup io |
| * |
| * 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() { } |
| }; |
| |
| // [27.6.1.4] standard basic_istream manipulators |
| /** |
| * @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); |
| |
| #ifdef __GXX_EXPERIMENTAL_CXX0X__ |
| // [27.7.1.6] Rvalue stream extraction |
| /** |
| * @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 _CharT, typename _Traits, typename _Tp> |
| inline basic_istream<_CharT, _Traits>& |
| operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x) |
| { return (__is >> __x); } |
| #endif // __GXX_EXPERIMENTAL_CXX0X__ |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #include <bits/istream.tcc> |
| |
| #endif /* _GLIBCXX_ISTREAM */ |
