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标准库头文件 <streambuf>

来自 cppreference.com
< cpp‎ | 头文件
 
 
标准库头文件
语言支持
概念
<concepts> (C++20)
诊断
<system_error> (C++11)

内存管理
<memory_resource> (C++17)  
元编程
<type_traits> (C++11)
<ratio> (C++11)
通用实用程序
<utility>
<tuple> (C++11)
<optional> (C++17)
<variant> (C++17)
<any> (C++17)
<debugging> (C++26)
<expected> (C++23)
<bitset>
<charconv> (C++17)
<format> (C++20)
<bit> (C++20)

字符串
<cuchar> (C++11)

容器
<flat_set> (C++23)
<span> (C++20)
<mdspan> (C++23)
<inplace_vector> (C++26)
迭代器
<iterator>
范围
<ranges> (C++20)
<generator> (C++23)
算法
数值
<cfenv> (C++11)
<complex>
<cmath>
<linalg> (C++26)
<numbers> (C++20)

时间
<chrono> (C++11)
本地化
<codecvt> (C++11/17/26*)
<text_encoding> (C++26)
输入/输出
<iosfwd>
<iostream>
<ios>
<streambuf>
<filesystem> (C++17)
<cstdio>
<cinttypes> (C++11)
<strstream> (C++98/26*)
正则表达式
<regex> (C++11)
并发支持
<stop_token> (C++20)
<thread> (C++11)
<atomic> (C++11)
<rcu> (C++26)
<stdatomic.h> (C++23)
<mutex> (C++11)
<shared_mutex> (C++14)

<condition_variable> (C++11)  
<semaphore> (C++20)
<latch> (C++20)

<barrier> (C++20)
<future> (C++11)
<hazard_pointer> (C++26)

C 兼容性
<cstdbool> (C++11/17/20*)  
<ccomplex> (C++11/17/20*)
<ctgmath> (C++11/17/20*)

<cstdalign> (C++11/17/20*)

<ciso646> (直到 C++20)

 

此头文件是 输入/输出 库的一部分。

内容

抽象一个原始设备
(类模板) [编辑]
streambuf std::basic_streambuf<char>
(typedef)
wstreambuf std::basic_streambuf<wchar_t>
(typedef)

[编辑] 提要

namespace std {
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_streambuf;
  using streambuf  = basic_streambuf<char>;
  using wstreambuf = basic_streambuf<wchar_t>;
}

[编辑] 类模板 std::basic_streambuf

namespace std {
  template<class CharT, class Traits = char_traits<CharT>>
  class basic_streambuf {
  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;
 
    virtual ~basic_streambuf();
 
    // locales
    locale   pubimbue(const locale& loc);
    locale   getloc() const;
 
    // buffer and positioning
    basic_streambuf* pubsetbuf(char_type* s, streamsize n);
    pos_type pubseekoff(off_type off, ios_base::seekdir way,
                        ios_base::openmode which
                          = ios_base::in | ios_base::out);
    pos_type pubseekpos(pos_type sp,
                        ios_base::openmode which
                          = ios_base::in | ios_base::out);
    int      pubsync();
 
    // get and put areas
    // get area
    streamsize in_avail();
    int_type snextc();
    int_type sbumpc();
    int_type sgetc();
    streamsize sgetn(char_type* s, streamsize n);
 
    // putback
    int_type sputbackc(char_type c);
    int_type sungetc();
 
    // put area
    int_type   sputc(char_type c);
    streamsize sputn(const char_type* s, streamsize n);
 
  protected:
    basic_streambuf();
    basic_streambuf(const basic_streambuf& rhs);
    basic_streambuf& operator=(const basic_streambuf& rhs);
 
    void swap(basic_streambuf& rhs);
 
    // get area access
    char_type* eback() const;
    char_type* gptr()  const;
    char_type* egptr() const;
    void       gbump(int n);
    void       setg(char_type* gbeg, char_type* gnext, char_type* gend);
 
    // put area access
    char_type* pbase() const;
    char_type* pptr() const;
    char_type* epptr() const;
    void       pbump(int n);
    void       setp(char_type* pbeg, char_type* pend);
 
    // virtual functions
    // locales
    virtual void imbue(const locale& loc);
 
    // buffer management and positioning
    virtual basic_streambuf* setbuf(char_type* s, streamsize n);
    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
                             ios_base::openmode which
                               = ios_base::in | ios_base::out);
    virtual pos_type seekpos(pos_type sp,
                             ios_base::openmode which
                               = ios_base::in | ios_base::out);
    virtual int      sync();
 
    // get area
    virtual streamsize showmanyc();
    virtual streamsize xsgetn(char_type* s, streamsize n);
    virtual int_type   underflow();
    virtual int_type   uflow();
 
    // putback
    virtual int_type   pbackfail(int_type c = Traits::eof());
 
    // put area
    virtual streamsize xsputn(const char_type* s, streamsize n);
    virtual int_type   overflow(int_type c = Traits::eof());
  };
}

[编辑] 缺陷报告

以下行为改变缺陷报告被追溯地应用于之前发布的 C++ 标准。

DR 应用于 已发布的行为 正确行为
LWG 56 C++98 showmanyc 的返回类型在概要中是 int 更正为 streamsize