[fstream.syn]

# 31 Input/output library [[input.output]](./#input.output)

## 31.10 File-based streams [[file.streams]](file.streams#fstream.syn)

### 31.10.1 Header <fstream> synopsis [fstream.syn]

[🔗](#header:%3cfstream%3e)

namespace std {// [[filebuf]](filebuf "31.10.3 Class template basic_­filebuf"), class template basic_filebuftemplate<class charT, class traits = char_traits<charT>>class basic_filebuf; template<class charT, class traits>void swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y); using filebuf = basic_filebuf<char>; using wfilebuf = basic_filebuf<wchar_t>; // [[ifstream]](ifstream "31.10.4 Class template basic_­ifstream"), class template basic_ifstreamtemplate<class charT, class traits = char_traits<charT>>class basic_ifstream; template<class charT, class traits>void swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y); using ifstream = basic_ifstream<char>; using wifstream = basic_ifstream<wchar_t>; // [[ofstream]](ofstream "31.10.5 Class template basic_­ofstream"), class template basic_ofstreamtemplate<class charT, class traits = char_traits<charT>>class basic_ofstream; template<class charT, class traits>void swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y); using ofstream = basic_ofstream<char>; using wofstream = basic_ofstream<wchar_t>; // [[fstream]](fstream "31.10.6 Class template basic_­fstream"), class template basic_fstreamtemplate<class charT, class traits = char_traits<charT>>class basic_fstream; template<class charT, class traits>void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y); using fstream = basic_fstream<char>; using wfstream = basic_fstream<wchar_t>;}

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10928)

The header [<fstream>](#header:%3cfstream%3e "31.10.1 Header <fstream> synopsis [fstream.syn]") defines four class templates and eight types
that associate stream buffers with files and assist
reading and writing files[.](#1.sentence-1)

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10934)

[*Note [1](#note-1)*:

The class template basic_filebuf treats a file as a source or
sink of bytes[.](#2.sentence-1)

In an environment that uses a large character set, the file
typically holds multibyte character sequences and the basic_filebuf object converts those multibyte sequences into wide character sequences[.](#2.sentence-2)

— *end note*]

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10942)

In subclause [[file.streams]](file.streams "31.10 File-based streams"), member functions taking arguments of const filesystem​::​path​::​value_type* are only provided on systems where filesystem​::​path​::​value_type ([[fs.class.path]](fs.class.path "31.12.6 Class path")) is not char[.](#3.sentence-1)

[*Note [2](#note-2)*:

These functions enable class path support for systems with a wide native path character type, such as wchar_t[.](#3.sentence-2)

— *end note*]