std::filesystem::path::c_str, std::filesystem::path::native, std::filesystem::path::operator string_type()

From cppreference.com
< cpp‎ | filesystem‎ | path
 
 
 
 
const value_type* c_str() const;
(1) (since C++17)
const string_type& native() const;
(2) (since C++17)
operator string_type() const;
(3) (since C++17)

Accesses the native path name as a character string.

1) Equivalent to native().c_str().
2) Returns the native string representation of the pathname by reference.
3) Returns the native string representation of the pathname by value.

Contents

[edit] Parameters

(none)

[edit] Return value

The native string representation of the pathname, using native syntax, native character type, and native character encoding. This string is suitable for use with OS APIs.

[edit] Exceptions

1,2)
noexcept specification:  
noexcept
  

[edit] Notes

The conversion function (3) is provided so that standard file-opening APIs that accept std::basic_string file names, such as the std::ifstream constructor, can use pathnames with no changes to code:

std::filesystem::path p = "/tmp/text.txt";
std::ifstream f(p);

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