std::formatter<std::filesystem::path>

 

C++

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Feature test macros (C++20)

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Filesystem library (C++17)

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Technical specifications

Symbols index

External libraries

 

Filesystem library

Classes
filesystem::path filesystem::filesystem_error filesystem::directory_entry filesystem::directory_iterator filesystem::recursive_directory_iterator      filesystem::file_status	filesystem::space_info filesystem::file_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options filesystem::file_time_type
Functions
filesystem::absolute filesystem::canonicalfilesystem::weakly_canonical filesystem::relativefilesystem::proximate filesystem::copy filesystem::copy_file filesystem::copy_symlink filesystem::create_directory filesystem::create_directories filesystem::create_hard_link filesystem::create_symlink filesystem::create_directory_symlink filesystem::current_path	filesystem::exists filesystem::equivalent filesystem::file_size filesystem::hard_link_count filesystem::last_write_time filesystem::permissions filesystem::read_symlink filesystem::remove filesystem::remove_all filesystem::rename filesystem::resize_file filesystem::space filesystem::status filesystem::symlink_status filesystem::temp_directory_path
File types
filesystem::is_block_file filesystem::is_character_file filesystem::is_directory filesystem::is_empty filesystem::status_known	filesystem::is_fifo filesystem::is_other filesystem::is_regular_file filesystem::is_socket filesystem::is_symlink

 

std::filesystem::path

Constants
path::native_formatpath::generic_formatpath::auto_format
Member functions
path::path path::~path path::operator= path::assign path::appendpath::operator/= path::concatpath::operator+= path::clear path::make_preferred path::remove_filename path::replace_filename path::replace_extension      path::swap path::compare path::beginpath::end	path::c_strpath::nativepath::operator string_type path::stringpath::u8stringpath::u16stringpath::u32stringpath::wstring path::generic_stringpath::generic_u8stringpath::generic_u16stringpath::generic_u32stringpath::generic_wstring path::lexically_normalpath::lexically_relativepath::lexically_proximate
Path decomposition
path::root_name path::root_directory path::root_path path::relative_path path::parent_path path::filename path::stem path::extension path::empty	path::has_root_pathpath::has_root_namepath::has_root_directorypath::has_relative_pathpath::has_parent_pathpath::has_filenamepath::has_stempath::has_extension path::is_absolutepath::is_relative
Non-member functions
operator==operator!=operator<operator<=operator>operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)	operator/ operator<<operator>> swap(std::filesystem::path) hash_value u8path
Helper Classes
hash<std::filesystem::path>
formatter<std::filesystem::path> (C++26)

 

Defined in header <filesystem>
template< class CharT > struct formatter<std::filesystem::path, CharT>;		(since C++26)

The template specialization of std::formatter for the std::filesystem::path class allows users to convert a pathname to its textual representation using formatting functions. This specialization is debug-enabled.

Format specification

The syntax of format specifications path-format-spec is:

fill-and-align (optional) width (optional) ?(optional) g(optional)

fill-and-align and width have the same meaning as in standard format specification.

The ? option is used to format the pathname as an escaped string.

The g option is used to specify that the pathname is in generic-format representation.

Member functions

set_debug_format	enables to format the pathname as an escaped string (public member function)
parse	parses the format specifier as specified by path-format-spec (public member function)
format	writes the formatted output as specified by path-format-spec (public member function)

std::formatter<std::filesystem::path>::set_debug_format

constexpr void set_debug_format();

Allows the current object to format pathname as an escaped string.

std::formatter<std::filesystem::path>::parse

constexpr auto parse( std::basic_format_parse_context<CharT>& ctx )     -> std::basic_format_parse_context<CharT>::iterator;

Parses the format specifiers as a path-format-spec and stores the parsed specifiers in the current object.

Returns an iterator past the end of the path-format-spec.

std::formatter<std::filesystem::path>::format

template< class FormatContext > auto format( const std::filesystem::path& p, FormatContext& ctx ) const     -> FormatContext::iterator;

Let s be p.generic<std::filesystem::path::value_type>() if the g option is used, otherwise p.native(). Writes s into ctx.out() as specified by path-format-spec.

For character transcoding of the pathname:

• The pathname is transcoded from the native encoding for wide character strings to UTF-8 with maximal subparts of ill-formed subsequences substituted with U+FFFD REPLACEMENT CHARACTER if
  • std::is_same_v<CharT, char> is true,
  • std::is_same_v<typename path::value_type, wchar_t> is true, and
  • ordinary literal encoding is UTF-8.
• Otherwise, no transcoding is performed if std::is_same_v<typename path::value_type, CharT> is true.
• Otherwise, transcoding is implementation-defined.

Returns an iterator past the end of the output range.

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_format_path	202403L	(C++26)	formatting support for std::filesystem::path

See also

formatter (C++20)

defines formatting rules for a given type (class template)