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

const value_type* c_str() const;	(1)	(filesystem TS)
const string_type& native() const;	(2)	(filesystem TS)
operator string_type() const;	(3)	(filesystem TS)

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.

Parameters

(none)

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.

Exceptions

1,2)

noexcept specification:

noexcept

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:

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

Example

Run this code

#include <cstdio>
#include <clocale>
#include <fstream>
#include <iostream>
#include <experimental/filesystem>
namespace fs = std::experimental::filesystem;

int main()
{
    std::setlocale(LC_ALL, "en_US.utf8");
    std::locale::global(std::locale("en_US.utf8"));

    fs::path p = fs::u8path(u8".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: .txt
File name in wide encoding: .txt

Language
Headers
Freestanding and hosted implementations
Named requirements
Language support library
Concepts library (C++20)
Diagnostics library
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)
Filesystem library (C++17)
Technical Specifications

Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals 2 TS)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Concepts (concepts TS)
Ranges (ranges TS)
Special mathematical functions (special math TR)