標準庫標頭檔案 <iosfwd>

 

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標準庫標頭檔案

語言支援 <cfloat> <climits> <compare> (C++20) <contracts> (C++26) <coroutine> (C++20) <csetjmp> <csignal> <cstdarg> <cstddef> <cstdint> (C++11) <cstdlib> <exception> <initializer_list> (C++11)    <limits> <new> <source_location> (C++20) <stdfloat> (C++23) <typeinfo> <version> (C++20) 概念 <concepts> (C++20) 診斷 <cassert> <cerrno> <debugging> (C++26) <stacktrace> (C++23) <stdexcept> <system_error> (C++11) 記憶體管理 <memory> <memory_resource> (C++17) <scoped_allocator> (C++11) 超程式設計 <type_traits> (C++11) <ratio> (C++11)

通用工具 <any> (C++17) <bitset> <bit> (C++20) <charconv> (C++17) <expected> (C++23) <format> (C++20) <functional> <optional> (C++17) <tuple> (C++11) <typeindex> (C++11) <utility> <variant> (C++17) 容器 <array> (C++11) <deque> <flat_map> (C++23) <flat_set> (C++23) <forward_list> (C++11) <hive> (C++26) <inplace_vector> (C++26)    <list> <map> <mdspan> (C++23) <queue> <set> <span> (C++20) <stack> <unordered_map> (C++11) <unordered_set> (C++11) <vector> 迭代器 <iterator> Ranges <generator> (C++23) <ranges> (C++20)

演算法 <algorithm> <numeric> 字串 <cctype> <cstring> <cuchar> (C++11) <cwchar> <cwctype> <string_view> (C++17) <string> 文字處理 <clocale> <codecvt> (C++11/17/26*) <locale> <regex> (C++11) <text_encoding> (C++26)    數值 <cfenv> (C++11) <cmath> <complex> <linalg> (C++26) <numbers> (C++20) <random> (C++11) <simd> (C++26) <valarray> 時間 <chrono> (C++11) <ctime> C 相容性 <ccomplex> (C++11/17/20*) <ciso646> (直到 C++20) <cstdalign> (C++11/17/20*) <cstdbool> (C++11/17/20*) <ctgmath> (C++11/17/20*)

輸入/輸出 <cinttypes> (C++11) <cstdio> <filesystem> (C++17) <fstream> <iomanip> <iosfwd> <iostream> <ios> <istream> <ostream> <print> (C++23) <spanstream> (C++23) <sstream> <streambuf> <strstream> (C++98/26*) <syncstream> (C++20) 併發支援 <atomic> (C++11) <barrier> (C++20) <condition_variable> (C++11) <future> (C++11) <hazard_pointer> (C++26) <latch> (C++20) <mutex> (C++11) <rcu> (C++26) <semaphore> (C++20) <shared_mutex> (C++14) <stdatomic.h> (C++23) <stop_token> (C++20) <thread> (C++11) 執行支援 <execution> (C++17)

 

此標頭檔案包含 輸入/輸出 庫的前向宣告。

前向宣告
定義於標頭檔案 <string>
std::char_traits	描述字元型別屬性的類模板 (類模板)
std::char_traits<char>	(類模板特化)
std::char_traits<wchar_t>	(類模板特化)
std::char_traits<char8_t> (C++20)	(類模板特化)
std::char_traits<char16_t> (C++11)	(類模板特化)
std::char_traits<char32_t> (C++11)	(類模板特化)
定義於標頭檔案 <memory>
allocator	預設分配器 (類模板)
定義於標頭檔案 <ios>
basic_ios	管理任意流緩衝區 (類模板)
fpos	表示流或檔案中的絕對位置 (類模板)
定義於標頭檔案 <streambuf>
basic_streambuf	抽象原始裝置 (類模板)
定義於標頭檔案 <ostream>
basic_ostream	包裝給定的抽象裝置（std::basic_streambuf） 並提供高階輸出介面 (類模板)
定義於標頭檔案 <istream>
basic_istream	包裝給定的抽象裝置（std::basic_streambuf） 並提供高階輸入介面 (類模板)
basic_iostream	包裝給定的抽象裝置（std::basic_streambuf） 並提供高階輸入/輸出介面 (類模板)
定義於標頭檔案 <fstream>
basic_filebuf	實現原始檔案裝置 (類模板)
basic_ifstream	實現高階檔案流輸入操作 (類模板)
basic_ofstream	實現高階檔案流輸出操作 (類模板)
basic_fstream	實現高階檔案流輸入/輸出操作 (類模板)
定義於標頭檔案 <sstream>
basic_stringbuf	實現原始字串裝置 (類模板)
basic_istringstream	實現高階字串流輸入操作 (類模板)
basic_ostringstream	實現高階字串流輸出操作 (類模板)
basic_stringstream	實現高階字串流輸入/輸出操作 (類模板)
定義於標頭檔案 <syncstream>
basic_syncbuf (C++20)	同步輸出裝置包裝器 (類模板)
basic_osyncstream (C++20)	同步輸出流包裝器 (類模板)
定義於標頭檔案 <spanstream>
basic_spanbuf (C++23)	實現原始固定字元緩衝區裝置 (類模板)
basic_ispanstream (C++23)	實現固定字元緩衝區輸入操作 (類模板)
basic_ospanstream (C++23)	實現固定字元緩衝區輸出操作 (類模板)
basic_spanstream (C++23)	實現固定字元緩衝區輸入/輸出操作 (類模板)
定義於標頭檔案 <strstream>
strstreambuf (在 C++98 中已廢棄)(在 C++26 中已移除)	實現原始字元陣列裝置 (類)
istrstream (在 C++98 中已廢棄)(在 C++26 中已移除)	實現字元陣列輸入操作 (類)
ostrstream (在 C++98 中已廢棄)(在 C++26 中已移除)	實現字元陣列輸出操作 (類)
strstream (在 C++98 中已廢棄)(在 C++26 中已移除)	實現字元陣列輸入/輸出操作 (類)
型別定義與特化
std::streampos	std::fpos<std::char_traits<char>::state_type>
std::wstreampos	std::fpos<std::char_traits<wchar_t>::state_type>
std::u8streampos	std::fpos<std::char_traits<char8_t>::state_type>
std::u16streampos	std::fpos<std::char_traits<char16_t>::state_type>
std::u32streampos	std::fpos<std::char_traits<char32_t>::state_type>
此外，對於此標頭檔案中宣告的每個類模板 std::basic_T，std::T 和 std::wT 分別宣告為 std::basic_T<char> 和 std::basic_T<wchar_t> 的同義詞。

概要

namespace std {
  template<class CharT> struct char_traits;
  template<> struct char_traits<char>;
  template<> struct char_traits<char8_t>;
  template<> struct char_traits<char16_t>;
  template<> struct char_traits<char32_t>;
  template<> struct char_traits<wchar_t>;
 
  template<class T> class allocator;
 
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_ios;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_streambuf;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_istream;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_ostream;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_iostream;
 
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_stringbuf;
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_istringstream;
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_ostringstream;
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_stringstream;
 
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_filebuf;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_ifstream;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_ofstream;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_fstream;
 
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_syncbuf;
  template<class CharT, class Traits = char_traits<CharT>,
           class Allocator = allocator<CharT>>
    class basic_osyncstream;
 
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_spanbuf;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_ispanstream;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_ospanstream;
  template<class CharT, class Traits = char_traits<CharT>>
    class basic_spanstream;
 
  template<class CharT, class Traits = char_traits<CharT>>
    class istreambuf_iterator;
  template<class CharT, class Traits = char_traits<CharT>>
    class ostreambuf_iterator;
 
  using ios  = basic_ios<char>;
  using wios = basic_ios<wchar_t>;
 
  using streambuf = basic_streambuf<char>;
  using istream   = basic_istream<char>;
  using ostream   = basic_ostream<char>;
  using iostream  = basic_iostream<char>;
 
  using stringbuf     = basic_stringbuf<char>;
  using istringstream = basic_istringstream<char>;
  using ostringstream = basic_ostringstream<char>;
  using stringstream  = basic_stringstream<char>;
 
  using filebuf  = basic_filebuf<char>;
  using ifstream = basic_ifstream<char>;
  using ofstream = basic_ofstream<char>;
  using fstream  = basic_fstream<char>;
 
  using syncbuf     = basic_syncbuf<char>;
  using osyncstream = basic_osyncstream<char>;
 
  using spanbuf     = basic_spanbuf<char>;
  using ispanstream = basic_ispanstream<char>;
  using ospanstream = basic_ospanstream<char>;
  using spanstream  = basic_spanstream<char>;
 
  using wstreambuf = basic_streambuf<wchar_t>;
  using wistream   = basic_istream<wchar_t>;
  using wostream   = basic_ostream<wchar_t>;
  using wiostream  = basic_iostream<wchar_t>;
 
  using wstringbuf     = basic_stringbuf<wchar_t>;
  using wistringstream = basic_istringstream<wchar_t>;
  using wostringstream = basic_ostringstream<wchar_t>;
  using wstringstream  = basic_stringstream<wchar_t>;
 
  using wfilebuf  = basic_filebuf<wchar_t>;
  using wifstream = basic_ifstream<wchar_t>;
  using wofstream = basic_ofstream<wchar_t>;
  using wfstream  = basic_fstream<wchar_t>;
 
  using wsyncbuf     = basic_syncbuf<wchar_t>;
  using wosyncstream = basic_osyncstream<wchar_t>;
 
  using wspanbuf     = basic_spanbuf<wchar_t>;
  using wispanstream = basic_ispanstream<wchar_t>;
  using wospanstream = basic_ospanstream<wchar_t>;
  using wspanstream  = basic_spanstream<wchar_t>;
 
  template<class State> class fpos;
  using streampos = fpos<char_traits<char>::state_type>;
  using wstreampos = fpos<char_traits<wchar_t>::state_type>;
  using u8streampos = fpos<char_traits<char8_t>::state_type>;
  using u16streampos = fpos<char_traits<char16_t>::state_type>;
  using u32streampos = fpos<char_traits<char32_t>::state_type>;
}
 
// deprecated
namespace std {
  class strstreambuf;
  class istrstream;
  class ostrstream;
  class strstream;
}