class template

std::basic_filebuf

template < class charT, class traits = char_traits<charT> >  class basic_filebuf;

File stream buffer

basic_streambuf
basic_filebuf

Stream buffer to read from and write to files.

Constructed without association, these objects are associated to a file by calling member open. Once open, all input/output operations performed on the object are reflected in the associated file.

Objects of this class may internally maintain an intermediate input buffer and/or an intermediate output buffer, where individual characters are read or written by i/o operations. These buffers are synchronized with the contents of the file once filled up, when explicitly requested to do so (sync), or when the object is closed.

Objects of this class may be explicitly made unbuffered by calling member pubsetbuf with both arguments set to zero (see member setbuf): Unbuffered file stream buffers perform the i/o operations directly on the file, without an intermediate buffer.

Access to the associated sequence of characters (i.e., the file) is given to streams by means of the interface offered by the virtual members inherited from basic_streambuf that are overriden in this class:

Template parameters

charT: Character type.
This shall be a non-array POD type.
Aliased as member type basic_filebuf::char_type.
traits: Character traits class that defines essential properties of the characters used by stream objects (see char_traits).
traits::char_type shall be the same as charT.
Aliased as member type basic_filebuf::traits_type.

Template instantiations

filebuf: File stream buffer (class)

wfilebuf: File stream buffer (wide) (class)

These instantiations are declared in <fstream>.

Member types

member type	definition	notes
`char_type`	The first template parameter (`charT`)
`traits_type`	The second template parameter (`traits`)	defaults to: `char_traits<charT>`
`int_type`	`traits_type::int_type`
`pos_type`	`traits_type::pos_type`	generally, the same as `streampos`
`off_type`	`traits_type::off_type`	generally, the same as `streamoff`

Public member functions

(constructor): Construct object (public member function)

(destructor): Destruct object (public member function)

operator=: Move-assignment (public member function)

swap: Swap file buffers (public member function)

File association

open: Open file (public member function)

is_open: Check if file is open (public member function)

close: Close file (public member function)

Public member functions inherited from `basic_streambuf`

Locales:

pubimbue: Imbue locale (public member function)

getloc: Get current locale (public member function)

Buffer management and positioning:

pubsetbuf: Set buffer array (public member function)

pubseekoff: Set internal position pointer to relative position (public member function)

pubseekpos: Set internal position pointer to absolute position (public member function)

pubsync: Synchronize stream buffer (public member function)

Input functions (get):

in_avail: Get number of character available to read (public member function)

snextc: Advance to next position and get character (public member function)

sbumpc: Get current character and advance to next position (public member function)

sgetc: Get current character (public member function)

sgetn: Get sequence of characters (public member function)

sputbackc: Put character back (public member function)

sungetc: Decrease current position (public member function)

Output functions (put):

sputc: Put character and advance to next position (public member function)

sputn: Put sequence of characters (public member function)

Protected virtual function overrides

showmanyc: Get number of characters available (public member function)

underflow: Get character on underflow (protected virtual member function)

uflow: Get character on overflow and advance position (protected virtual member function)

pbackfail: Put character back on underflow (protected virtual member function)

overflow: Put character on overflow (protected virtual member function)

setbuf: Set buffer (protected virtual member function)

seekoff: Set internal position to relative position (protected virtual member function)

seekpos: Set position pointer to absolute position (protected virtual member function)

sync: Synchornize buffer (protected virtual member function)

imbue: Imbue locale (protected virtual member function)

The class also inherits other protected members that are non-virtual or not overridden. See base class basic_streambuf for more details.

Non-member function overloads

swap: Swap file buffers (function template)