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

< cpp‎ | filesystem‎ | path
template< class CharT, class Traits = std::char_traits<CharT>,

          class Alloc = std::allocator<CharT> >

    string( const Alloc& a = Alloc() ) const;
(1) (since C++17)
(2) (since C++17)
std::string string() const;
std::wstring wstring() const;
std::string u8string() const;
std::u16string u16string() const;
std::u32string u32string() const;

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.
1) All memory allocations are performed by a.
2) The result encoding in the case of u8string() is always UTF-8.


[edit] Parameters


[edit] Return value

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

[edit] Exceptions


[edit] Example

#include <cstdio>
#ifdef _MSC_VER
#include <io.h>
#include <fcntl.h>
#include <locale>
#include <clocale>
#include <fstream>
#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;
int main()
#ifdef _MSC_VER
    _setmode(_fileno(stderr), _O_WTEXT);
    std::setlocale(LC_ALL, "");
    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")
                std::fopen(p.c_str(), "r")
        int ch;
        while((ch=fgetc(f))!= EOF) putchar(ch);
    // 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';


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

[edit] See also

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