std::filesystem::path::string,std::filesystem::path::wstring,std::filesystem::path::u8string,std::filesystem::path::u16string,std::filesystem::path::u32string (3) - Linux Manuals

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

NAME

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

Synopsis

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