private static bool AssertFileMode(string file, FileMode mode)
{
bool flag = StdioFileStream.FileExists(file);
if (mode == FileMode.CreateNew && flag)
{
throw new IOException("File exists and FileMode.CreateNew specified");
}
if ((mode == FileMode.Open || mode == FileMode.Truncate) && !flag)
{
throw new FileNotFoundException("File doesn't exist and FileMode.Open specified", file);
}
return(flag);
}