标准库头文件 <istream>

来自cppreference.com
< cpp‎ | header
 
 
 

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) [编辑]
std::istream basic_istream<char>
(typedef)
std::wistream 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) [编辑]
std::iostream basic_iostream<char>
(typedef)
std::wiostream basic_iostream<wchar_t>
(typedef)

目录

函数

提取字符和字符数组
(函数模板) [编辑]
操纵符
消耗空白符
(函数模板) [编辑]

[编辑] 概要

namespace std {
    template <class charT, class traits = char_traits<charT> >
        class basic_istream;
    typedef basic_istream<char>    istream;
    typedef basic_istream<wchar_t> wistream;
 
    template <class charT, class traits = char_traits<charT> >
        class basic_iostream;
    typedef basic_istream<char>    iostream;
    typedef basic_istream<wchar_t> wiostream;
 
    template <class charT, class traits>
        basic_istream<charT,traits>& ws(basic_istream<charT,traits>& is);
 
    template <class charT, class traits, class T>
        basic_istream<charT, traits>&
        operator>>(basic_istream<charT, traits>&& is, T& x);
 
    // 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>
        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*);
 
}


[编辑] std::basic_istream

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):
    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;
 
    // 构造函数/析构函数:
    explicit basic_istream(basic_streambuf<char_type,traits>* sb);
    virtual ~basic_istream();
 
    // 前缀/后缀:
    class sentry;
 
    // 有格式输入:
    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);
 
    // 无格式输入:
    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:
    basic_istream(const basic_istream& rhs) = delete;
    basic_istream(basic_istream&& rhs);
 
    // 赋值/交换:
    basic_istream& operator=(const basic_istream& rhs) = delete;
    basic_istream& operator=(basic_istream&& rhs);
    void swap(basic_istream& rhs);
 
};

[编辑] std::basic_iostream

template <class charT, class traits = char_traits<charT> >
class basic_iostream :
    public basic_istream<charT,traits>,
    public basic_ostream<charT,traits> {
 
public:
    // 类型
    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;
 
    // 构造函数/析构函数
    explicit basic_iostream(basic_streambuf<charT,traits>* sb);
    virtual ~basic_iostream();
 
protected:
    basic_iostream(const basic_iostream& rhs) = delete;
    basic_iostream(basic_iostream&& rhs);
 
    // 赋值/交换
    basic_iostream& operator=(const basic_iostream& rhs) = delete;
    basic_iostream& operator=(basic_iostream&& rhs);
    void swap(basic_iostream& rhs);
};