Boost C++ Libraries: Ticket #3884: boost fstream 'enforces' in AND out mode. It should be be possible to open a read-only file using fstream.

Steven Watanabe — Mon, 01 Feb 2010 21:53:01 GMT

If you know at compile time whether you are only going to read/write you should use ifstream or ofstream instead.

Tue, 02 Feb 2010 17:54:06 GMT

If you know at compile time whether you are only going to read/write you should use ifstream or ofstream instead.

File opening mode is decided at run-time and it workes fine when working with std::fstream objects (at least with Microsoft's implementation of it, didn't try on gcc).

We also need a common base class to hold the open file stream objects (ifstream does not inherit from fstream, it's the other way round). If we use ifstream object when opening files only for reading, we won't be able to pass the object around with other fstream objects.

cc set

Tue, 02 Feb 2010 18:00:04 GMT

cc schngrg@… added

Also, boost::fstream is implemented as a wrapper over std::fstream (it uses a std::fstream object internally), which means that if any changes to 'mode' value are indeed needed, then the std::fstream::open() can do that internally. I am unable to see the reason for boost's wrapper to change its value before passing it to std::fstream.

(We are using boost's fstream because it lets us directly use wpath filenames which is is huge convenience compared to using std::fstream's char*)

status changed; resolution set

Beman Dawes — Wed, 10 Feb 2010 17:21:45 GMT

status new → closed
resolution → fixed

(In [59622]) Fix #3884

Beman Dawes — Wed, 10 Feb 2010 17:22:49 GMT

(In [59623]) Fix #3884