标准库标头 <sstream>

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

技术规范

符号索引

外部库

 

标准库标头

注：修订记号中的反斜杠 '/' 意味着此标头被弃用和/或被移除。

语言支持
<cstddef> <cstdlib> <version> (C++20) <limits> <climits>	<cfloat> <cstdint> (C++11) <stdfloat> (C++23) <new> <typeinfo>	<source_location> (C++20) <exception> <initializer_list> (C++11) <compare> (C++20)	<coroutine> (C++20) <csignal> <csetjmp> <cstdarg>
概念
<concepts> (C++20)
诊断
<stdexcept> <stacktrace> (C++23)	<cassert>	<cerrno>	<system_error> (C++11)
内存管理
<memory>	<memory_resource> (C++17)	<scoped_allocator> (C++11)
元编程
<type_traits> (C++11)	<ratio> (C++11)
通用工具
<utility> <tuple> (C++11) <optional> (C++17) <variant> (C++17)	<any> (C++17) <expected> (C++23) <bitset>	<functional> <typeindex> (C++11) <execution> (C++17)	<charconv> (C++17) <format> (C++20) <bit> (C++20)
字符串
<string_view> (C++17) <string>	<cctype> <cwctype>	<cstring> <cwchar>	<cuchar> (C++11)
容器
<array> (C++11) <deque> <forward_list> (C++11) <list>	<vector> <map> <set> <unordered_map> (C++11)	<unordered_set> (C++11) <queue> <stack> <flat_map> (C++23)	<flat_set> (C++23) <span> (C++20) <mdspan> (C++23)
迭代器
<iterator>
范围
<ranges> (C++20)	<generator> (C++23)
算法
<algorithm>	<execution>
数值
<cfenv> (C++11) <complex>	<random> (C++11) <valarray>	<cmath>	<numbers> (C++20)
日期时间
<chrono> (C++11)	<ctime>
本地化
<locale>	<clocale>	<codecvt> (C++11/17)
输入/输出
<iosfwd> <iostream> <ios> <streambuf>	<istream> <ostream> <iomanip> <print> (C++23)	<sstream> <spanstream> (C++23) <fstream> <syncstream> (C++20)	<filesystem> (C++17) <cstdio> <cinttypes> (C++11) <strstream> (C++98/)
正则表达式
<regex>
并发支持
<stop_token> (C++20) <thread> (C++11) <atomic> (C++11)	<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)
C 兼容
<cstdbool> (C++11/17/20)   <ccomplex> (C++11/17/20)	<ctgmath> (C++11/17/20)	<cstdalign> (C++11/17/20)	<ciso646> (C++20 前)

 

此标头是输入/输出库的一部分。

类
basic_stringbuf	实现原生字符串设备 (类模板)
basic_istringstream	实现高层字符串流输入操作 (类模板)
basic_ostringstream	实现高层字符串流输出操作 (类模板)
basic_stringstream	实现高层字符串流输入/输出操作 (类模板)
stringbuf	std::basic_stringbuf<char> (typedef)
wstringbuf	std::basic_stringbuf<wchar_t> (typedef)
istringstream	std::basic_istringstream<char> (typedef)
wistringstream	std::basic_istringstream<wchar_t> (typedef)
ostringstream	std::basic_ostringstream<char> (typedef)
wostringstream	std::basic_ostringstream<wchar_t> (typedef)
stringstream	std::basic_stringstream<char> (typedef)
wstringstream	std::basic_stringstream<wchar_t> (typedef)
函数
std::swap(std::basic_stringbuf) (C++11)	特化 std::swap 算法 (函数模板)
std::swap(std::basic_istringstream) (C++11)	特化 std::swap 算法 (函数模板)
std::swap(std::basic_ostringstream) (C++11)	特化 std::swap 算法 (函数模板)
std::swap(std::basic_stringstream) (C++11)	特化 std::swap 算法 (函数模板)

概要

namespace std {
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_stringbuf;
 
  using stringbuf  = basic_stringbuf<char>;
  using wstringbuf = basic_stringbuf<wchar_t>;
 
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_istringstream;
 
  using istringstream  = basic_istringstream<char>;
  using wistringstream = basic_istringstream<wchar_t>;
 
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_ostringstream;
  using ostringstream  = basic_ostringstream<char>;
  using wostringstream = basic_ostringstream<wchar_t>;
 
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_stringstream;
  using stringstream  = basic_stringstream<char>;
  using wstringstream = basic_stringstream<wchar_t>;
}

类模板 std::basic_stringbuf

namespace std {
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
  class basic_stringbuf : public basic_streambuf<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;
    using allocator_type = Allocator;
 
    // 构造函数
    basic_stringbuf() : basic_stringbuf(ios_base::in | ios_base::out) {}
    explicit basic_stringbuf(ios_base::openmode which);
    explicit basic_stringbuf(
      const basic_string<CharT, Traits, Allocator>& s,
      ios_base::openmode which = ios_base::in | ios_base::out);
    explicit basic_stringbuf(const Allocator& a)
      : basic_stringbuf(ios_base::in | ios_base::out, a) {}
    basic_stringbuf(ios_base::openmode which, const Allocator& a);
    explicit basic_stringbuf(
      basic_string<CharT, Traits, Allocator>&& s,
      ios_base::openmode which = ios_base::in | ios_base::out);
    template<class SAlloc>
      basic_stringbuf(
        const basic_string<CharT, Traits, SAlloc>& s, const Allocator& a)
        : basic_stringbuf(s, ios_base::in | ios_base::out, a) {}
    template<class SAlloc>
      basic_stringbuf(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which, const Allocator& a);
    template<class SAlloc>
      explicit basic_stringbuf(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which = ios_base::in | ios_base::out);
    basic_stringbuf(const basic_stringbuf&) = delete;
    basic_stringbuf(basic_stringbuf&& rhs);
    basic_stringbuf(basic_stringbuf&& rhs, const Allocator& a);
 
    // 赋值与交换
    basic_stringbuf& operator=(const basic_stringbuf&) = delete;
    basic_stringbuf& operator=(basic_stringbuf&& rhs);
    void swap(basic_stringbuf& rhs) noexcept(see below);
 
    // 获取器与设置器
    allocator_type get_allocator() const noexcept;
 
    basic_string<CharT, Traits, Allocator> str() const &;
    template<class SAlloc>
      basic_string<CharT,Traits,SAlloc> str(const SAlloc& sa) const;
    basic_string<CharT, Traits, Allocator> str() &&;
    basic_string_view<CharT, Traits> view() const noexcept;
 
    void str(const basic_string<CharT, Traits, Allocator>& s);
    template<class SAlloc>
      void str(const basic_string<CharT, Traits, SAlloc>& s);
    void str(basic_string<CharT, Traits, Allocator>&& s);
 
  protected:
    // 覆写的虚函数
    int_type underflow() override;
    int_type pbackfail(int_type c = Traits::eof()) override;
    int_type overflow (int_type c = Traits::eof()) override;
    basic_streambuf<CharT, Traits>* setbuf(CharT*, streamsize) override;
 
    pos_type seekoff(off_type off, ios_base::seekdir way,
                     ios_base::openmode which
                      = ios_base::in | ios_base::out) override;
    pos_type seekpos(pos_type sp,
                     ios_base::openmode which
                      = ios_base::in | ios_base::out) override;
 
  private:
    ios_base::openmode mode;                        // 仅用于阐释
    basic_string<CharT, Traits, Allocator> buf;     // 仅用于阐释
    void init_buf_ptrs();                           // 仅用于阐释
  };
 
  template<class CharT, class Traits, class Allocator>
    void swap(basic_stringbuf<CharT, Traits, Allocator>& x,
              basic_stringbuf<CharT, Traits, Allocator>& y) noexcept(noexcept(x.swap(y)));
}

类模板 std::basic_istringstream

namespace std {
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
  class basic_istringstream : public basic_istream<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;
    using allocator_type = Allocator;
 
    // 构造函数
    basic_istringstream() : basic_istringstream(ios_base::in) {}
    explicit basic_istringstream(ios_base::openmode which);
    explicit basic_istringstream(
      const basic_string<CharT, Traits, Allocator>& s,
      ios_base::openmode which = ios_base::in);
    basic_istringstream(ios_base::openmode which, const Allocator& a);
    explicit basic_istringstream(
      basic_string<CharT, Traits, Allocator>&& s,
      ios_base::openmode which = ios_base::in);
    template<class SAlloc>
      basic_istringstream(
        const basic_string<CharT, Traits, SAlloc>& s, const Allocator& a)
        : basic_istringstream(s, ios_base::in, a) {}
    template<class SAlloc>
      basic_istringstream(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which, const Allocator& a);
    template<class SAlloc>
      explicit basic_istringstream(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which = ios_base::in);
    basic_istringstream(const basic_istringstream&) = delete;
    basic_istringstream(basic_istringstream&& rhs);
 
    // 赋值与交换
    basic_istringstream& operator=(const basic_istringstream&) = delete;
    basic_istringstream& operator=(basic_istringstream&& rhs);
    void swap(basic_istringstream& rhs);
 
    // 成员
    basic_stringbuf<CharT, Traits, Allocator>* rdbuf() const;
    basic_string<CharT, Traits, Allocator> str() const &;
    template<class SAlloc>
      basic_string<CharT,Traits,SAlloc> str(const SAlloc& sa) const;
    basic_string<CharT, Traits, Allocator> str() &&;
    basic_string_view<CharT, Traits> view() const noexcept;
 
    void str(const basic_string<CharT, Traits, Allocator>& s);
    template<class SAlloc>
      void str(const basic_string<CharT, Traits, SAlloc>& s);
    void str(basic_string<CharT, Traits, Allocator>&& s);
 
  private:
    basic_stringbuf<CharT, Traits, Allocator> sb;   // 仅用于阐释
  };
 
  template<class CharT, class Traits, class Allocator>
    void swap(basic_istringstream<CharT, Traits, Allocator>& x,
              basic_istringstream<CharT, Traits, Allocator>& y);
}

类模板 std::basic_ostringstream

namespace std {
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
  class basic_ostringstream : 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;
    using allocator_type = Allocator;
 
    // 构造函数
    basic_ostringstream() : basic_ostringstream(ios_base::out) {}
    explicit basic_ostringstream(ios_base::openmode which);
    explicit basic_ostringstream(
      const basic_string<CharT, Traits, Allocator>& s,
      ios_base::openmode which = ios_base::out);
    basic_ostringstream(ios_base::openmode which, const Allocator& a);
    explicit basic_ostringstream(
      basic_string<CharT, Traits, Allocator>&& s,
      ios_base::openmode which = ios_base::out);
    template<class SAlloc>
      basic_ostringstream(
        const basic_string<CharT, Traits, SAlloc>& s, const Allocator& a)
        : basic_ostringstream(s, ios_base::out, a) {}
    template<class SAlloc>
      basic_ostringstream(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which, const Allocator& a);
    template<class SAlloc>
      explicit basic_ostringstream(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which = ios_base::out);
    basic_ostringstream(const basic_ostringstream&) = delete;
    basic_ostringstream(basic_ostringstream&& rhs);
 
    // 赋值与交换
    basic_ostringstream& operator=(const basic_ostringstream&) = delete;
    basic_ostringstream& operator=(basic_ostringstream&& rhs);
    void swap(basic_ostringstream& rhs);
 
    // 成员
    basic_stringbuf<CharT, Traits, Allocator>* rdbuf() const;
 
    basic_string<CharT, Traits, Allocator> str() const &;
    template<class SAlloc>
      basic_string<CharT,Traits,SAlloc> str(const SAlloc& sa) const;
    basic_string<CharT, Traits, Allocator> str() &&;
    basic_string_view<CharT, Traits> view() const noexcept;
 
    void str(const basic_string<CharT, Traits, Allocator>& s);
    template<class SAlloc>
      void str(const basic_string<CharT, Traits, SAlloc>& s);
    void str(basic_string<CharT, Traits, Allocator>&& s);
 
   private:
    basic_stringbuf<CharT, Traits, Allocator> sb;   // 仅用于阐释
  };
 
  template<class CharT, class Traits, class Allocator>
    void swap(basic_ostringstream<CharT, Traits, Allocator>& x,
              basic_ostringstream<CharT, Traits, Allocator>& y);
}

类模板 std::basic_stringstream

namespace std {
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
  class basic_stringstream : public basic_iostream<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;
    using allocator_type = Allocator;
 
    // 构造函数
    basic_stringstream() : basic_stringstream(ios_base::out | ios_base::in) {}
    explicit basic_stringstream(ios_base::openmode which);
    explicit basic_stringstream(
      const basic_string<CharT, Traits, Allocator>& s,
      ios_base::openmode which = ios_base::out | ios_base::in);
    basic_stringstream(ios_base::openmode which, const Allocator& a);
    explicit basic_stringstream(
      basic_string<CharT, Traits, Allocator>&& s,
      ios_base::openmode which = ios_base::out | ios_base::in);
    template<class SAlloc>
      basic_stringstream(
        const basic_string<CharT, Traits, SAlloc>& s, const Allocator& a)
        : basic_stringstream(s, ios_base::out | ios_base::in, a) {}
    template<class SAlloc>
      basic_stringstream(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which, const Allocator& a);
    template<class SAlloc>
      explicit basic_stringstream(
        const basic_string<CharT, Traits, SAlloc>& s,
        ios_base::openmode which = ios_base::out | ios_base::in);
    basic_stringstream(const basic_stringstream&) = delete;
    basic_stringstream(basic_stringstream&& rhs);
 
    // 赋值与交换
    basic_stringstream& operator=(const basic_stringstream&) = delete;
    basic_stringstream& operator=(basic_stringstream&& rhs);
    void swap(basic_stringstream& rhs);
 
    // 成员
    basic_stringbuf<CharT, Traits, Allocator>* rdbuf() const;
 
    basic_string<CharT, Traits, Allocator> str() const &;
    template<class SAlloc>
      basic_string<CharT,Traits,SAlloc> str(const SAlloc& sa) const;
    basic_string<CharT, Traits, Allocator> str() &&;
    basic_string_view<CharT, Traits> view() const noexcept;
 
    void str(const basic_string<CharT, Traits, Allocator>& s);
    template<class SAlloc>
      void str(const basic_string<CharT, Traits, SAlloc>& s);
    void str(basic_string<CharT, Traits, Allocator>&& s);
 
  private:
    basic_stringbuf<CharT, Traits> sb;  // 仅用于阐释
  };
 
  template<class CharT, class Traits, class Allocator>
    void swap(basic_stringstream<CharT, Traits, Allocator>& x,
              basic_stringstream<CharT, Traits, Allocator>& y);
}

缺陷报告

下列更改行为的缺陷报告追溯地应用于以前出版的 C++ 标准。

缺陷报告	应用于	出版时的行为	正确行为
LWG 170	C++98	std::basic_ostringstream 和 std::basic_stringstream 的概要中缺失了 traits_type 的定义	已补充
LWG 251	C++98	std::basic_stringbuf、std::basic_istringstream、 std::basic_ostringstream 和 std::basic_stringstream 的概要中缺失了 allocator_type 的定义	已补充