31 Input/output library [input.output]

31.12 File systems [filesystems]

31.12.6 Class path [fs.class.path]

31.12.6.5 Members [fs.path.member]

31.12.6.5.1 Constructors [fs.path.construct]

path() noexcept;
Postconditions: empty() == true.
path(const path& p); path(path&& p) noexcept;
Effects: Constructs an object of class path having the same pathname in the native and generic formats, respectively, as the original value of p.
In the second form, p is left in a valid but unspecified state.
path(string_type&& source, format fmt = auto_format);
Effects: Constructs an object of class path for which the pathname in the detected-format of source has the original value of source ([fs.path.fmt.cvt]), converting format if required ([fs.path.fmt.cvt]).
source is left in a valid but unspecified state.
template<class Source> path(const Source& source, format fmt = auto_format); template<class InputIterator> path(InputIterator first, InputIterator last, format fmt = auto_format);
Effects: Let s be the effective range of source ([fs.path.req]) or the range [first, last), with the encoding converted if required ([fs.path.cvt]).
Finds the detected-format of s ([fs.path.fmt.cvt]) and constructs an object of class path for which the pathname in that format is s.
template<class Source> path(const Source& source, const locale& loc, format fmt = auto_format); template<class InputIterator> path(InputIterator first, InputIterator last, const locale& loc, format fmt = auto_format);
Mandates: The value type of Source and InputIterator is char.
Effects: Let s be the effective range of source or the range [first, last), after converting the encoding as follows:
  • If value_type is wchar_t, converts to the native wide encoding ([fs.path.type.cvt]) using the codecvt<wchar_t, char, mbstate_t> facet of loc.
  • Otherwise a conversion is performed using the codecvt<wchar_t, char, mbstate_t> facet of loc, and then a second conversion to the current ordinary encoding.
Finds the detected-format of s ([fs.path.fmt.cvt]) and constructs an object of class path for which the pathname in that format is s.
[Example 1: 
A string is to be read from a database that is encoded in ISO/IEC 8859-1, and used to create a directory: namespace fs = std::filesystem; std::string latin1_string = read_latin1_data(); codecvt_8859_1<wchar_t> latin1_facet; std::locale latin1_locale(std::locale(), latin1_facet); fs::create_directory(fs::path(latin1_string, latin1_locale));
For POSIX-based operating systems, the path is constructed by first using latin1_facet to convert ISO/IEC 8859-1 encoded latin1_string to a wide character string in the native wide encoding ([fs.path.type.cvt]).
The resulting wide string is then converted to an ordinary character pathname string in the current native ordinary encoding.
If the native wide encoding is UTF-16 or UTF-32, and the current native ordinary encoding is UTF-8, all of the characters in the ISO/IEC 8859-1 character set will be converted to their Unicode representation, but for other native ordinary encodings some characters may have no representation.
For Windows-based operating systems, the path is constructed by using latin1_facet to convert ISO/IEC 8859-1 encoded latin1_string to a UTF-16 encoded wide character pathname string.
All of the characters in the ISO/IEC 8859-1 character set will be converted to their Unicode representation.
— end example]