std::basic_ofstream<CharT,Traits>::is_open

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Input/output library

I/O manipulators

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

strstreambuf (deprecated in C++98)

basic_syncbuf (C++20)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

istrstream (deprecated in C++98)

ostrstream (deprecated in C++98)

strstream (deprecated in C++98)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

std::basic_ofstream

Member functions

basic_ofstream::basic_ofstream

basic_ofstream::operator= (C++11)

basic_ofstream::swap (C++11)

basic_ofstream::rdbuf

File operations

basic_ofstream::is_open

basic_ofstream::open

basic_ofstream::close

Non-member functions

basic_ofstream::swap(std::basic_ofstream) (C++11)

 

bool is_open();		(until C++11)
bool is_open() const;		(since C++11)

Checks if the file stream has an associated file.

Effectively calls rdbuf()->is_open().

Parameters

(none)

Return value

true if the file stream has an associated file, false otherwise

See also

open	opens a file and associates it with the stream (public member function)
close	closes the associated file (public member function)