std::filesystem::path::string, std::filesystem::path::wstring, std::filesystem::path::u8string, std::filesystem::path::u16string, std::filesystem::path::u32string
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< cpp | filesystem | path
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
std::filesystem::path
path::stringpath::u8stringpath::u16stringpath::u32stringpath::wstring
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
template< class CharT, class Traits = std::char_traits <CharT>,
(1)
(since C++17)
class Alloc = std::allocator <CharT> >
std::basic_string <CharT,Traits,Alloc>
(2)
(since C++17)
std::string string() const;
std::wstring wstring() const;
std::u16string u16string() const;
std::u32string u32string() const;
(3)
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_typeis char, conversion, if any, is system-dependent. This is the case on typical POSIX systems (such as Linux), where native encoding is UTF-8 andstring()performs no conversion. - Otherwise, if
path::value_typeis 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_typeis char16_t, native encoding is UTF-16 and the conversion method is unspecified. - Otherwise, if
path::value_typeis char32_t, native encoding is UTF-32 and the conversion method is unspecified. - Otherwise, if
path::value_typeis 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.
[edit] Parameters
(none)
[edit] Return value
The internal pathname in native pathname format, converted to specified string type.
[edit] Exceptions
May throw implementation-defined exceptions.
[edit] 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年02月01日) 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