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

From cppreference.com
< cpp‎ | filesystem‎ | path
 
 
 
 
template< class CharT, class Traits = std::char_traits<CharT>

          class Alloc = std::allocator<CharT> >
std::basic_string<CharT,Traits,Alloc>

    string( const Alloc& a = Allocator() ) const;
(1) (since C++17)
(2) (since C++17)
std::string string() const;
std::wstring wstring() const;
std::string u8string() const;
std::u16string u16string() const;
std::u32string u32string() 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 if 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.
1) All memory allocations are performed by a.
2) The result encoding in the case of u8string() is always UTF-8.

Contents

[edit] Parameters

(none)

[edit] Return value

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

[edit] Exceptions

(none)

[edit] Example

#include <cstdio>
#include <clocale>
#include <fstream>
#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;
 
int main()
{
    std::setlocale(LC_ALL, "en_US.utf8");
    std::locale::global(std::locale("en_US.utf8"));
 
    fs::path p = fs::u8path(u8"要らない.txt");
 
    // native string representation can be used with OS APIs
    std::ofstream(p) << "File contents"; // this uses operator string()
    if(std::FILE* f = std::fopen(p.c_str(), "r")) {
        int ch;
        while((ch=fgetc(f))!= EOF) putchar(ch);
        std::fclose(f);
    }
 
    // multibyte and wide representation can be used for output
    std::cout.imbue(std::locale());
    std::cout << "\nFile name in narrow multibyte encoding: "
              << p.string() << '\n';
 
    std::wcerr.imbue(std::locale());
    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

[edit] See also

returns the path in generic pathname format converted to a string
(public member function)