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Is there a way to create a fstream, ifstream or ofstream object with a wchar_t* or wstring filename? (c++)

January 5, 2025

I am tring to compile some code wrote for the msvc compiler with msys2 gcc (msys2-msys2 not msys2-mingw) and it contains

wstring filename;
ifstream file(filename);

I tried to find a way to use _wfopen() witch I can import from msvcrt.dll but I couldn’t find a way to override the underlying __basic_file type which contains a FILE*

I also tried defining

#define _GLIBCXX_HAVE__WFOPEN 1
#define _GLIBCXX_USE_WCHAR_T 1

but that lead to linkage errors (here)

I also tried exporting a function create_ifstream(const wchar_t*) from mingw-w64 gcc, but ifstream doesn’t have a copy constructor so it either lead to compiler errors or to a segmaentation fault at runtime

Does anybody know how I could open a file with a wide character name (It’s windows so converting the file name to UTF-8 won’t work with some filenames)

>Solution :

<filesystem> can do that.

#include <filesystem>
#include <fstream>
#include <string>

namespace fs = std::filesystem;

int main() {
  std::wstring some_path;
  std::ifstream file1(fs::path(some_path));
  std::ifstream file2(fs::path(L"some_path"));
}

https://godbolt.org/z/h14eGrErz – gcc and msvc.