std::filesy...th::wstring,(3)

okay bestie, welcome to the std::filesy...th::wstring,(3) page from the C++ Standard Libary — yes, the header literally spells it Libary, and we are keeping that detail, no cap 💅

🌸 NAME 🌸

std::filesystem::path::string,std::filesystem::path::wstring, -
std::filesystem::path::string,std::filesystem::path::wstring,

that's the name section, exactly as the original gives it 🫶

✨ SYNOPSIS ✨

okay so the synopsis is giving chaotic cppreference formatting, so here are the exact tokens so nothing gets lost 💖

std::filesystem::path::u32string

template< class CharT, class Traits =
std::char_traits<CharT>,
                                                          (since
          class Alloc = std::allocator<CharT> >             (1)
 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       (since
    std::string u8string() const;
 C++17)       C++17)
                                                                    (3)
 (until
                                                                         C++20)
    std::u8string u8string() const;
 (since
                                                                         C++20)

so (1) is the (since C++17) template overload, (2) is (since C++17), and (3) is the (until C++20) / (since C++20) moment. iconic formatting, honestly 😭

---

so what does it actually do? it returns the internal pathname in native pathname format, converted to the 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.

and the numbered notes from the original:

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

🎀 PARAMETERS 🎀

(none)

literally none, bestie. no parameters. periodt 💅

🦋 RETURN VALUE 🦋

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

💀 EXCEPTIONS 💀

May throw implementation-defined exceptions.

so yeah, it can throw implementation-defined exceptions — no cap, that's the whole warning 🫶

🍓 EXAMPLE 🍓

// Run this code

#include <clocale>
#include <cstdio>
#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);
}

🌈 POSSIBLE 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_string
• generic_wstring — returns the path in generic pathname format converted to a string
• generic_u8string — (public member function)
• generic_u16string
• generic_u32string

🌟 CATEGORY 🌟

• Uses of dcl rev begin with nonempty note

kisses and sparkles 🫶 this page's footer energy is: http://cppreference.com, version/date 2024.06.10, and the footer title std::filesy...th::wstring,(3). bye bestie 💖