Re: [boost] Report from Berlin C++ Standards Committee meeting

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-04-11 17:23:41

Alexander Nasonov wrote:
> Peter Dimov wrote:
>>     std::ifstream is( "http://www.example.com/file.zip" );
>>     std::ofstream os( "file.zip" );
>>     os << is.rdbuf();
>>
>> No proposal required, in principle.
>
> Are you aware of (a) ambiguity and (b) potential security hole?

Yes, I am aware of both. It's a tradeoff.

> (a)
>> mkdir http:
>> mkdir http:/www.example.com
>> touch http:/www.example.com/file.zip
>> file http://www.example.com/file.zip
> http://www.example.com/file.zip: empty
>
> (b)
> If you replace the first line with something more generic, for example
> with:
>     std::ifstream is( argv[1] );
>
> it becomes unclear that the code might send requests to the net.

The code can already send requests to the net; an example is

    \\www.example.com\share\file

under Windows. In most cases, allowing existing code to seamlessly read from 
remote files over HTTP or FTP is a feature. PHP, for example, does that in 
its fopen, and most graphical shells also maintain this illusion.

Anyway, I just wanted to illustrate the fact that standard library 
implementors already have the ability to add HTTP/FTP functionality; 
unfortunately, none have done so. C++ is a somewhat conservative language. 
:-)

The obvious alternative is, of course,

    std::tr2::iurlstream is( "http://www.example.com/file.zip" );

which does require a proposal, albeit a relatively simple one. ASIO need not 
be involved in any way, and the implementation under Windows can use 
WinInet, for example.