在线文档教程
首页 技术教程 开发文档 觅分类 ICON图标
技术教程 开发文档 觅分类 ICON图标
Bootstrap 4
Bootstrap 3
C
C++
算法 | Algorithm
原子性操作 | Atomic operations
概念 | Concepts
容器 | Containers
动态内存管理 | Dynamic memory management
文件系统 | Filesystem
输入/输出 | Input/output
C-style file input/output
egptr
gptr
Input/output library
Input/output manipulators
operator<<(std::basic_ostream)
operator>>(std::basic_istream)
std::basic_filebuf
std::basic_filebuf::basic_filebuf
std::basic_filebuf::close
std::basic_filebuf::imbue
std::basic_filebuf::open
std::basic_filebuf::overflow
std::basic_filebuf::pbackfail
std::basic_filebuf::seekoff
std::basic_filebuf::seekpos
std::basic_filebuf::setbuf
std::basic_filebuf::showmanyc
std::basic_filebuf::swap
std::basic_filebuf::sync
std::basic_filebuf::uflow
std::basic_filebuf::underflow
std::basic_fstream
std::basic_fstream::basic_fstream
std::basic_fstream::close
std::basic_fstream::is_open
std::basic_fstream::open
std::basic_fstream::rdbuf
std::basic_fstream::swap
std::basic_ifstream
std::basic_ifstream::basic_ifstream
std::basic_ifstream::close
std::basic_ifstream::is_open
std::basic_ifstream::open
std::basic_ifstream::rdbuf
std::basic_ifstream::swap
std::basic_ios
std::basic_ios::bad
std::basic_ios::basic_ios
std::basic_ios::clear
std::basic_ios::copyfmt
std::basic_ios::eof
std::basic_ios::exceptions
std::basic_ios::fail
std::basic_ios::fill
std::basic_ios::good
std::basic_ios::imbue
std::basic_ios::init
std::basic_ios::move
std::basic_ios::narrow
std::basic_ios::operator bool
std::basic_ios::rdbuf
std::basic_ios::rdstate
std::basic_ios::setstate
std::basic_ios::set_rdbuf
std::basic_ios::swap
std::basic_ios::tie
std::basic_ios::widen
std::basic_iostream
std::basic_iostream::basic_iostream
std::basic_iostream::swap
std::basic_istream
std::basic_istream::basic_istream
std::basic_istream::gcount
std::basic_istream::get
std::basic_istream::getline
std::basic_istream::ignore
std::basic_istream::operator>>
std::basic_istream::peek
std::basic_istream::putback
std::basic_istream::read
std::basic_istream::readsome
std::basic_istream::seekg
std::basic_istream::sentry
std::basic_istream::swap
std::basic_istream::sync
std::basic_istream::tellg
std::basic_istream::unget
std::basic_istringstream
std::basic_istringstream::basic_istringstream
std::basic_istringstream::rdbuf
std::basic_istringstream::str
std::basic_istringstream::swap
std::basic_ofstream
std::basic_ofstream::basic_ofstream
std::basic_ofstream::close
std::basic_ofstream::is_open
std::basic_ofstream::open
std::basic_ofstream::rdbuf
std::basic_ofstream::swap
std::basic_ostream
std::basic_ostream::basic_ostream
std::basic_ostream::flush
std::basic_ostream::operator<<
std::basic_ostream::put
std::basic_ostream::seekp
std::basic_ostream::sentry
std::basic_ostream::swap
std::basic_ostream::tellp
std::basic_ostream::write
std::basic_ostringstream
std::basic_ostringstream::basic_ostringstream
std::basic_ostringstream::rdbuf
std::basic_ostringstream::str
std::basic_ostringstream::swap
std::basic_streambuf
std::basic_streambuf::basic_streambuf
std::basic_streambuf::eback
std::basic_streambuf::epptr
std::basic_streambuf::gbump
std::basic_streambuf::getloc
std::basic_streambuf::imbue
std::basic_streambuf::in_avail
std::basic_streambuf::overflow
std::basic_streambuf::pbackfail
std::basic_streambuf::pbase
std::basic_streambuf::pbump
std::basic_streambuf::pptr
std::basic_streambuf::pubimbue
std::basic_streambuf::pubseekoff
std::basic_streambuf::pubseekpos
std::basic_streambuf::pubsetbuf
std::basic_streambuf::pubsync
std::basic_streambuf::sbumpc
std::basic_streambuf::seekoff
std::basic_streambuf::seekpos
std::basic_streambuf::setbuf
std::basic_streambuf::setg
std::basic_streambuf::setp
std::basic_streambuf::sgetc
std::basic_streambuf::sgetn
std::basic_streambuf::showmanyc
std::basic_streambuf::snextc
std::basic_streambuf::sputbackc
std::basic_streambuf::sputc
std::basic_streambuf::sputn
std::basic_streambuf::sungetc
std::basic_streambuf::swap
std::basic_streambuf::sync
std::basic_streambuf::uflow
std::basic_streambuf::underflow
std::basic_streambuf::xsgetn
std::basic_streambuf::xsputn
std::basic_stringbuf
std::basic_stringbuf::basic_stringbuf
std::basic_stringbuf::overflow
std::basic_stringbuf::pbackfail
std::basic_stringbuf::seekoff
std::basic_stringbuf::seekpos
std::basic_stringbuf::setbuf
std::basic_stringbuf::str
std::basic_stringbuf::swap
std::basic_stringbuf::underflow
std::basic_stringstream
std::basic_stringstream::basic_stringstream
std::basic_stringstream::rdbuf
std::basic_stringstream::str
std::basic_stringstream::swap
std::boolalpha
std::cerr
std::cin
std::clearerr
std::clog
std::cout
std::dec
std::defaultfloat
std::endl
std::ends
std::fclose
std::feof
std::ferror
std::fflush
std::fgetc
std::fgetpos
std::fgets
std::fgetwc
std::fgetws
std::fixed
std::flush
std::fopen
std::fpos
std::fpos::state
std::fprintf
std::fputc
std::fputs
std::fputwc
std::fputws
std::fread
std::freopen
std::fscanf
std::fseek
std::fsetpos
std::ftell
std::fwide
std::fwprintf
std::fwrite
std::fwscanf
std::getc
std::getchar
std::gets
std::getwchar
std::get_money
std::get_time
std::hex
std::hexfloat
std::internal
std::iostream_category
std::ios_base
std::ios_base::event
std::ios_base::event_callback
std::ios_base::failure
std::ios_base::flags
std::ios_base::fmtflags
std::ios_base::getloc
std::ios_base::imbue
std::ios_base::Init
std::ios_base::iostate
std::ios_base::ios_base
std::ios_base::iword
std::ios_base::openmode
std::ios_base::precision
std::ios_base::pword
std::ios_base::register_callback
std::ios_base::seekdir
std::ios_base::setf
std::ios_base::sync_with_stdio
std::ios_base::unsetf
std::ios_base::width
std::ios_base::xalloc
std::io_errc
std::istrstream
std::istrstream::istrstream
std::istrstream::rdbuf
std::istrstream::str
std::is_error_code_enum<std::io_errc>
std::left
std::make_error_code(std::io_errc)
std::make_error_condition(std::io_errc)
std::noboolalpha
std::noshowbase
std::noshowpoint
std::noshowpos
std::noskipws
std::nounitbuf
std::nouppercase
std::oct
std::ostrstream
std::ostrstream::freeze
std::ostrstream::ostrstream
std::ostrstream::pcount
std::ostrstream::rdbuf
std::ostrstream::str
std::perror
std::printf
std::putc
std::putchar
std::puts
std::putwchar
std::put_money
std::put_time
std::quoted
std::remove
std::rename
std::resetiosflags
std::rewind
std::right
std::scanf
std::scientific
std::setbase
std::setbuf
std::setfill
std::setiosflags
std::setprecision
std::setvbuf
std::setw
std::showbase
std::showpoint
std::showpos
std::skipws
std::snprintf
std::sprintf
std::sscanf
std::streamoff
std::streamsize
std::strstream
std::strstream::freeze
std::strstream::pcount
std::strstream::rdbuf
std::strstream::str
std::strstream::strstream
std::strstreambuf
std::strstreambuf::freeze
std::strstreambuf::overflow
std::strstreambuf::pbackfail
std::strstreambuf::pcount
std::strstreambuf::seekoff
std::strstreambuf::seekpos
std::strstreambuf::setbuf
std::strstreambuf::str
std::strstreambuf::strstreambuf
std::strstreambuf::underflow
std::swap(std::basic_filebuf)
std::swap(std::basic_fstream)
std::swap(std::basic_ifstream)
std::swap(std::basic_istringstream)
std::swap(std::basic_ofstream)
std::swap(std::basic_ostringstream)
std::swap(std::basic_stringbuf)
std::swap(std::basic_stringstream)
std::swprintf
std::swscanf
std::tmpfile
std::tmpnam
std::ungetc
std::ungetwc
std::unitbuf
std::uppercase
std::vfprintf
std::vfscanf
std::vfwprintf
std::vfwscanf
std::vprintf
std::vscanf
std::vsnprintf
std::vsprintf
std::vsscanf
std::vswprintf
std::vswscanf
std::vwprintf
std::vwscanf
std::wcerr
std::wcin
std::wclog
std::wcout
std::wprintf
std::ws
std::wscanf
迭代器 | Iterator
关键词 | Keywords
语言 | Language
本土化 | Localizations
数字 | Numerics
规律表达 | Regular expressions
标准库头文件 | Standard library header files
字符串 | Strings
线程支持 | Thread support
应用 | Utilities
Clojure 1.8
Codeigniter 3
CSS
Docker 17
Electron
Elixir 1.5
Erlang 20
Eslint
Express
Git
Go
HTML
HTTP
Immutable 3.8.1
JavaScript
Lodash 4
Lua 5.3
Nginx
PHP
Phpunit 6
Python
React
React native
Redis
Redux
Ruby 2.4
Sass
Scikit image
Socket.IO
Sqlite
SVG
TensorFlow Guide
Typescript
Underscore
Vue 2
Webpack
Xslt & Xpath
Yarn
RxJS 5
Rollup.js
Babel
Parcel
MobX
Koa
Angular
Gulp
Grunt
Stylelint
Standard JS
Element UI
iView UI
Lavas
Mint UI
PostCSS
ThinkJS
Nest
npm
Node.js教程
JSON教程
Groovy教程
vb.net教程
Storm入门教程
Hibernate 教程
Slick教程
MongoDB教程
Yii 2.0

std::basic_filebuf::is_open

性病：基本[医]filebuf：：is[医]开着的营业的

bool is_open() const;​​

回报true如果最近的电话open()成功了，没有人呼吁close()从那以后。

参数

%280%29

返回值

true如果相关文件打开，false否则。

注记

此函数通常由std::basic_fstream::is_open()...

例

二次

#include <fstream>
#include <iostream>
 
int main()
{
    std::ifstream fs("test.txt"
    std::filebuf fb;
    fb.open("test.txt", std::ios_base::in
    std::cout << std::boolalpha
              << "direct call: " << fb.is_open() << '\n'
              << "through streambuf: " << fs.rdbuf()->is_open() << '\n'
              << "through fstream: " << fs.is_open() << '\n';
}

二次

产出：

二次

direct call: true
through streambuf: true
through fstream: true

二次

另见

openopens a file and configures it as the associated character sequence (public member function)
closeflushes the put area buffer and closes the associated file (public member function)

 © cppreference.com

在CreativeCommonsAttribution下授权-ShareAlike未移植许可v3.0。

http：//en.cppreference.com/w/cpp/io/basic[医]filebuf/is[医]开着的营业的

  • 黔ICP备2021005045号