I was using C++ function:

_int64 FileSize(const wchar_t* name)
{
    WIN32_FILE_ATTRIBUTE_DATA fad;
    if (!GetFileAttributesEx(name, GetFileExInfoStandard, &fad))
        return -1; // error condition, could call GetLastError to find out more
    LARGE_INTEGER size;
    size.HighPart = fad.nFileSizeHigh;
    size.LowPart = fad.nFileSizeLow;
    return size.QuadPart;
}

to get the file size of a big 5 GB text file which was working well in Visual Studio x64 5 years ago. After recent Visual Studio updates it stopped working. How to fix it?

I was trying to use _stat64 function but got the problem with conversion of wchar_t* to char*:

_int64 FileSize(const wchar_t* name) {
    struct _stat64i32 buf;
    int result;
    char timebuf[26];
    //char* filename = "crt_stat.c";
    errno_t err;

    result = _wstat64(name, &buf);
    return buf.st_size;
}

but I got the error:
The argument of type “_stat64i32 *” is incompatible with the parameter of type “_stat64 *”.