Annex D (normative) Compatibility features [depr]

D.23 Deprecated filesystem path factory functions [depr.fs.path.factory]

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template<class Source> path u8path(const Source& source); template<class InputIterator> path u8path(InputIterator first, InputIterator last);
1
#
Requires: The source and [first, last) sequences are UTF-8 encoded.
The value type of Source and InputIterator is char or char8_­t.
Source meets the requirements specified in [fs.path.req].
2
#
Returns:
  • (2.1)
    If value_­type is char and the current native narrow encoding ([fs.path.type.cvt]) is UTF-8, return path(source) or path(first, last); otherwise,
  • (2.2)
    if value_­type is wchar_­t and the native wide encoding is UTF-16, or if value_­type is char16_­t or char32_­t, convert source or [first, last) to a temporary, tmp, of type string_­type and return path(tmp); otherwise,
  • (2.3)
    convert source or [first, last) to a temporary, tmp, of type u32string and return path(tmp).
3
#
Remarks: Argument format conversion ([fs.path.fmt.cvt]) applies to the arguments for these functions.
How Unicode encoding conversions are performed is unspecified.
4
#
[Example
:
A string is to be read from a database that is encoded in UTF-8, and used to create a directory using the native encoding for filenames: 
namespace fs = std::filesystem;
std::string utf8_string = read_utf8_data();
fs::create_directory(fs::u8path(utf8_string));
For POSIX-based operating systems with the native narrow encoding set to UTF-8, no encoding or type conversion occurs.
For POSIX-based operating systems with the native narrow encoding not set to UTF-8, a conversion to UTF-32 occurs, followed by a conversion to the current native narrow encoding.
Some Unicode characters may have no native character set representation.
For Windows-based operating systems a conversion from UTF-8 to UTF-16 occurs.
— end example
]
[Note
:
The example above is representative of a historical use of filesystem​::​u8path.
Passing a std​::​u8string to path's constructor is preferred for an indication of UTF-8 encoding more consistent with path's handling of other encodings.
— end note
]