Re: [boost] possible problem with boost::iostreams::file_descriptor

Subject: Re: [boost] possible problem with boost::iostreams::file_descriptor
From: Eric MALENFANT (Eric.Malenfant_at_[hidden])
Date: 2009-06-11 09:50:01

Zachary Turner wrote:
> Eric MALENFANT wrote:
>> Zachary Turner wrote:
>>> Otherwise following
>>> code (Windows) asserts, even though I don't think it should:
>>> 
>>> bool is_open(HANDLE h) { return h && h!=INVALID_HANDLE_VALUE;}
>>> 
>>> HANDLE h = ::CreateFile("C:\\autoexec.bat", GENERIC_READ,
>>> FILE_SHARE_READ|FILE_SHARE_WRITE,NULL,OPEN_EXISTING,FILE_ATTRI
>>> BUTE_NORMAL,NULL); 
>>> 
>>> boost::iostreams::file_descriptor fd(h, false);
>>> 
>>> BOOST_ASSERT(fd.is_open() == is_open(h));
>>> 
>> Wouldn't changing:
>>    bool is_open() const { return pimpl_->flags_ != 0; } to:
>>    bool is_open() const { return pimpl_->handle_ != -1; }
>> be a better and/or simpler fix?
>>
> I blame the fact that it was 1 AM when I wrote that.  Not really sure
> what I was thinking tbh :D 

... and I blame the fact that I was not wearing my glasses while
checking if my reply was redundant:

eg wrote:
> I think there may be a related bug report : 
> https://svn.boost.org/trac/boost/ticket/2817

The ticket eg refers to also suggests to "fix" is_open() by validating
handle_'s value.

> Although I think it should compare
> against both -1 and 0, since neither indicates a valid handle.

For a Windows HANDLE maybe, but ain't 0 a valid file descriptor value (I
tought it was stdin)?