std::{{{1}}}::

{{{1}}}();	(1)
explicit {{{1}}}( const char* filename,          ios_base::openmode mode =	(2)
explicit {{{1}}}( const string& filename,                                            ios_base::openmode mode =	(3)	(since C++11)
{{{1}}}( {{{1}}}&& other );	(4)	(since C++11)
{{{1}}}( const {{{1}}}& rhs) = delete;	(5)	(since C++11)

Constructs new file stream.

1) Default constructor: constructs a stream that is not associated with a file: default-constructs the std::basic_filebuf and constructs the base with the pointer to this default-constructed std::basic_filebuf member.

2) First, performs the same steps as the default constructor, then asssociates the stream with a file by calling . If the open() call returns a null pointer, sets setstate(failbit).

3) Same as (filename.c_str(), mode).

4) Move constructor. First, move-constructs the base class from other (which does not affect the rdbuf() pointer), then move-constructs the std::basic_filebuf member, then calls this->set_rdbuf() to install the new basic_filebuf as the rdbuf() pointer in the base class.

5) The copy-constructor is deleted: this class is not copyable.

Parameters

filename	-	the name of the file to be opened
mode	-	specifies stream open mode. It is bitmask type, the following constants are defined: Constant Explanation app seek to the end of stream before each write binary open in binary mode in open for reading out open for writing trunc discard the contents of the stream when opening ate seek to the end of stream immediately after open noreplace (C++23) open in exclusive mode
other	-	another file stream to use as source

Example

Run this code

#include <fstream>
#include <utility>
#include <string>
int main()
{
 
}

See also

open	opens a file and associates it with the stream (public member function of std::{{{1}}})
open	opens a file and configures it as the associated character sequence (public member function of std::basic_filebuf<CharT,Traits>)
set_rdbuf	replaces the rdbuf without clearing its error state (protected member function)