Re: [boost] Interest in simple unformatted binary stream I/O?

Subject: Re: [boost] Interest in simple unformatted binary stream I/O?
From: Beman Dawes (bdawes_at_[hidden])
Date: 2011-05-27 07:54:36

On Fri, Apr 29, 2011 at 7:13 AM, Max Sobolev <macsmr_at_[hidden]> wrote:
> On 29.04.2011 11:52, Mathias Gaunard wrote:
>>>
>>> int main()
>>> {
>>> fstream f("binary_stream_example.dat",
>>> std::ios_base::trunc | std::ios_base::in | std::ios_base::out |
>>> std::ios_base::binary);
>>>
>>> int32_t x = 0x01020304;
>>> int32_t y = 0;
>>>
>>> f<< bin(x); // write 4 bytes
>>> f.seekg(0);
>>> f>> bin(y); // read 4 bytes
>>
>> I think it's a bad idea.
>>
>> If you want to do that kind of thing, you should use the streambuf
>> abstraction directly, along with its sgetn and sputn member functions.
>> It will be much more efficient.
>
> I am not agree.
> (If you *want* to use the streambuf directly, you should :) But don't force
> everyone to use this low-level tool.)
>
> I think binary stream IO shouldn't be implemented on the manipulator-like
> basis, an independent raw_stream class with minimal and full functionality
> is better.
> Then below I don't tied to proposed syntax (on the manipulator-like basis).
>
> A stream provide automatic "type deduction" / type safety, therefore an user
> shouldn't specify the type by hand:
>
> double d;
> char c;
> raw_stream raw;
> raw << d << c;
> raw >> d >> c;

That's a different problem. It addresses the case where all I/O is raw
binary, yet still stream oriented.

The use case I'm concerned with is where a regular stream sometimes
needs to treat integers as binary.

--Beman