标准库头文件 <istream>
此头文件是输入/输出库的一部分。
| 包装给定的抽象设备（std::basic_streambuf） 并提供高层输入接口 (类模板) | |
| std::istream | std::basic_istream<char> (typedef) |
| std::wistream | std::basic_istream<wchar_t> (typedef) |
| 包装给定的抽象设备（std::basic_streambuf） 并提供高层输入/输出接口 (类模板) | |
| std::iostream | std::basic_iostream<char> (typedef) |
| std::wiostream | std::basic_iostream<wchar_t> (typedef) |
函数 | |
| 提取字符和字符数组 (函数模板) | |
操纵符 | |
| 消耗空白符 (函数模板) | |
概要
namespace std { template<class CharT, class Traits = char_traits<CharT>> class basic_istream; using istream = basic_istream<char>; using wistream = basic_istream<wchar_t>; template<class CharT, class Traits = char_traits<CharT>> class basic_iostream; using iostream = basic_iostream<char>; using wiostream = basic_iostream<wchar_t>; template<class CharT, class Traits> basic_istream<CharT, Traits>& ws(basic_istream<CharT, Traits>& is); template<class Istream, class T> Istream&& operator>>(Istream&& is, T&& x); }
类模板 std::basic_istream
namespace std { template<class CharT, class Traits = char_traits<CharT>> class basic_istream : virtual public basic_ios<CharT, Traits> { public: // 类型（继承自 basic_ios ） using char_type = CharT; using int_type = typename Traits::int_type; using pos_type = typename Traits::pos_type; using off_type = typename Traits::off_type; using traits_type = Traits; // 构造函数/析构函数 explicit basic_istream(basic_streambuf<CharT, Traits>* sb); virtual ~basic_istream(); // 前置工序/后置工序 class sentry; // 有格式输出 basic_istream<CharT, Traits>& operator>>(basic_istream<CharT, Traits>& (*pf)(basic_istream<CharT, Traits>&)); basic_istream<CharT, Traits>& operator>>(basic_ios<CharT, Traits>& (*pf)(basic_ios<CharT, Traits>&)); basic_istream<CharT, Traits>& operator>>(ios_base& (*pf)(ios_base&)); basic_istream<CharT, Traits>& operator>>(bool& n); basic_istream<CharT, Traits>& operator>>(short& n); basic_istream<CharT, Traits>& operator>>(unsigned short& n); basic_istream<CharT, Traits>& operator>>(int& n); basic_istream<CharT, Traits>& operator>>(unsigned int& n); basic_istream<CharT, Traits>& operator>>(long& n); basic_istream<CharT, Traits>& operator>>(unsigned long& n); basic_istream<CharT, Traits>& operator>>(long long& n); basic_istream<CharT, Traits>& operator>>(unsigned long long& n); basic_istream<CharT, Traits>& operator>>(float& f); basic_istream<CharT, Traits>& operator>>(double& f); basic_istream<CharT, Traits>& operator>>(long double& f); basic_istream<CharT, Traits>& operator>>(void*& p); basic_istream<CharT, Traits>& operator>>(basic_streambuf<char_type, Traits>* sb); // 无格式输出 streamsize gcount() const; int_type get(); basic_istream<CharT, Traits>& get(char_type& c); basic_istream<CharT, Traits>& get(char_type* s, streamsize n); basic_istream<CharT, Traits>& get(char_type* s, streamsize n, char_type delim); basic_istream<CharT, Traits>& get(basic_streambuf<char_type, Traits>& sb); basic_istream<CharT, Traits>& get(basic_streambuf<char_type, Traits>& sb, char_type delim); basic_istream<CharT, Traits>& getline(char_type* s, streamsize n); basic_istream<CharT, Traits>& getline(char_type* s, streamsize n, char_type delim); basic_istream<CharT, Traits>& ignore(streamsize n = 1, int_type delim = Traits::eof()); int_type peek(); basic_istream<CharT, Traits>& read (char_type* s, streamsize n); streamsize readsome(char_type* s, streamsize n); basic_istream<CharT, Traits>& putback(char_type c); basic_istream<CharT, Traits>& unget(); int sync(); pos_type tellg(); basic_istream<CharT, Traits>& seekg(pos_type); basic_istream<CharT, Traits>& seekg(off_type, ios_base::seekdir); protected: // 复制/移动构造函数 basic_istream(const basic_istream&) = delete; basic_istream(basic_istream&& rhs); // 赋值与交换 basic_istream& operator=(const basic_istream&) = delete; basic_istream& operator=(basic_istream&& rhs); void swap(basic_istream& rhs); }; // 字符提取模板 template<class CharT, class Traits> basic_istream<CharT, Traits>& operator>>(basic_istream<CharT, Traits>&, CharT&); template<class Traits> basic_istream<char, Traits>& operator>>(basic_istream<char, Traits>&, unsigned char&); template<class Traits> basic_istream<char, Traits>& operator>>(basic_istream<char, Traits>&, signed char&); template<class CharT, class Traits, size_t N> basic_istream<CharT, Traits>& operator>>(basic_istream<CharT, Traits>&, CharT(&)[N]); template<class Traits, size_t N> basic_istream<char, Traits>& operator>>(basic_istream<char, Traits>&, unsigned char(&)[N]); template<class Traits, size_t N> basic_istream<char, Traits>& operator>>(basic_istream<char, Traits>&, signed char(&)[N]); }
类 std::basic_istream::sentry
namespace std { template<class CharT, class Traits = char_traits<CharT>> class basic_istream<CharT, Traits>::sentry { bool ok_; // 仅用于阐释 public: explicit sentry(basic_istream<CharT, Traits>& is, bool noskipws = false); ~sentry(); explicit operator bool() const { return ok_; } sentry(const sentry&) = delete; sentry& operator=(const sentry&) = delete; }; }
类模板 std::basic_iostream
namespace std { template<class CharT, class Traits = char_traits<CharT>> class basic_iostream : public basic_istream<CharT, Traits>, public basic_ostream<CharT, Traits> { public: using char_type = CharT; using int_type = typename Traits::int_type; using pos_type = typename Traits::pos_type; using off_type = typename Traits::off_type; using traits_type = Traits; // 构造函数 explicit basic_iostream(basic_streambuf<CharT, Traits>* sb); // 析构函数 virtual ~basic_iostream(); protected: // 构造函数 basic_iostream(const basic_iostream&) = delete; basic_iostream(basic_iostream&& rhs); // 赋值与交换 basic_iostream& operator=(const basic_iostream&) = delete; basic_iostream& operator=(basic_iostream&& rhs); void swap(basic_iostream& rhs); }; }