NAME¶

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

Synopsis¶

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)

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¶

May throw implementation-defined exceptions.

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