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

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;

std::string string() const;

std::wstring wstring() const;

std::u16string u16string() const;

std::u32string u32string() const;

std::string u8string() const;

std::u8string u8string() 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.
• Otherwise, if path::value_type is char8_t, native encoding is UTF-8 and the conversion method is unspecified.

Parameters

(none).

Return value

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

Exceptions

May throw implementation-defined exceptions.

Example

#include <cstdio>
#include <clocale>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <locale>
 
int main()
{
    const char* const localeName = "ja_JP.utf-8";
    std::setlocale(LC_ALL, localeName);
    std::locale::global(std::locale(localeName));
 
    const std::filesystem::path p(u8"要らない.txt");
    std::ofstream(p) << "File contents";
 
    // native string representation can be used with OS APIs
    if (std::FILE* const f = std::fopen(p.string().c_str(), "r"))
    {
        for (int ch; (ch = std::fgetc(f)) != EOF; )
            std::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';
 
    // wstring() will throw in stdlibc++ (as per gcc-12.1.0), see:
    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95048
    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102839
    // works with more recent gcc-12.2.1 (2023/02/01) and clang-10+
    std::wcout << "File name in wide encoding: " << p.wstring() << '\n';
 
    std::filesystem::remove(p);
}

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