std::filesystem::path::string, std::filesystem::path::wstring, std::filesystem::path::u8string, std::filesystem::path::u16string, std::filesystem::path::u32string

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

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
swap(path)
hash_value
operator==operator!=operator<operator<=operator>operator>=
operator/
operator<<operator>>
u8path

 

template< class CharT, class Traits = std::char_traits<CharT>,           class Alloc = std::allocator<CharT> > std::basic_string<CharT,Traits,Alloc>     string( const Alloc& a = Alloc() ) const;	(1)	(since C++17)
	(2)	(since C++17)
std::string string() const;
std::wstring wstring() const;
std::u16string u16string() const;
std::u32string u32string() const;
			(3)
std::string u8string() const;					(since C++17) (until C++20)
std::u8string u8string() const;					(since C++20)

Returns the internal pathname in native pathname format, converted to specific string type. Conversion, if any, is performed as follows:

• If path::value_type is char, conversion, if any, is system-dependent. This is the case on typical POSIX systems (such as Linux), where native encoding is UTF-8 and string() performs no conversion.
• Otherwise, if path::value_type is wchar_t, conversion, if any, is unspecified. This is the case on Windows, where wchar_t is 16 bit and the native encoding is UTF-16.
• Otherwise, if path::value_type is char16_t, native encoding is UTF-16 and the conversion method is unspecified.
• Otherwise, if path::value_type is char32_t, native encoding is UTF-32 and the conversion method is unspecified.
• Otherwise, if path::value_type is char8_t, native encoding is UTF-8 and the conversion method is unspecified.

1) All memory allocations are performed by a.

3) The result encoding in the case of u8string() is always UTF-8.

Parameters

(none)

Return value

The internal pathname in native pathname format, converted to specified string type.

Exceptions

(none)

Example

Run this code

#include <cstdio>
#ifdef _MSC_VER
#include <io.h>
#include <fcntl.h>
#else
#include <locale>
#include <clocale>
#endif
#include <fstream>
#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;
 
int main()
{
#ifdef _MSC_VER
    _setmode(_fileno(stderr), _O_WTEXT);
#else
    std::setlocale(LC_ALL, "");
    std::locale::global(std::locale(""));
    std::cout.imbue(std::locale());
    std::wcerr.imbue(std::locale());
#endif
 
    fs::path p = fs::u8path(u8"要らない.txt");
    std::ofstream(p) << "File contents"; // Prior to LWG2676 uses operator string_type()
                                         // on MSVC, where string_type is wstring, only
                                         // works due to non-standard extension.
                                         // Post-LWG2676 uses new fstream constructors
 
    // native string representation can be used with OS APIs
    if (std::FILE* f =
#ifdef _MSC_VER
                _wfopen(p.c_str(), L"r")
#else
                std::fopen(p.c_str(), "r")
#endif
        )
    {
        int ch;
        while((ch=fgetc(f))!= EOF) putchar(ch);
        std::fclose(f);
    }
 
    // multibyte and wide representation can be used for output
    std::cout << "\nFile name in narrow multibyte encoding: " << p.string() << '\n';
    std::wcerr << "File name in wide encoding: " << p.wstring() << '\n';
 
    fs::remove(p);
}

Output:

File contents
File name in narrow multibyte encoding: 要らない.txt
File name in wide encoding: 要らない.txt

See also

generic_stringgeneric_wstringgeneric_u8stringgeneric_u16stringgeneric_u32string

returns the path in generic pathname format converted to a string (public member function)