29 Input/output library [input.output]

29.9 File-based streams [file.streams]

29.9.1 Header <fstream> synopsis [fstream.syn]

namespace std { template<class charT, class traits = char_traits<charT>> class basic_filebuf; using filebuf = basic_filebuf<char>; using wfilebuf = basic_filebuf<wchar_t>; template<class charT, class traits = char_traits<charT>> class basic_ifstream; using ifstream = basic_ifstream<char>; using wifstream = basic_ifstream<wchar_t>; template<class charT, class traits = char_traits<charT>> class basic_ofstream; using ofstream = basic_ofstream<char>; using wofstream = basic_ofstream<wchar_t>; template<class charT, class traits = char_traits<charT>> class basic_fstream; using fstream = basic_fstream<char>; using wfstream = basic_fstream<wchar_t>; }

The header <fstream> defines four class templates and eight types that associate stream buffers with files and assist reading and writing files.

[Note 1:

The class template basic_filebuf treats a file as a source or sink of bytes.

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.

— end note]

In subclause [file.streams], member functions taking arguments of const filesystem::path::value_type* are only be provided on systems where filesystem::path::value_type ([fs.class.path]) is not char.

[Note 2:

These functions enable class path support for systems with a wide native path character type, such as wchar_t.

— end note]