binary_iostreams_kanze.txt

俄罗斯高人Mamaich的Pocket gcc编译器（运行在PocketPC上）的全部源代码。

From: James Kanze <[e-mail]>
Newsgroups: comp.lang.c++.moderated
Subject: Re: binary iostreams ?
Date: 3 Feb 2001 14:28:19 -0500
Message-ID: <[e-mail]>

"Plinio Conti" <[e-mail]> writes:

|>  Why std c++ library stream classes are only text-oriented?

Because that is the only universally recognized format.

|>  I mean, if I want to write an int, a float, etc. AS IT IS I can't
|>  use streams, because they write and read a human readable text
|>  format of numbers.

Correct.

|>  Does anyone know how to solve the problem?

It depends on what you really want to do.  If you are just dumping a
block of memory to disk, in order to free up memory, and will reread it
later in the same run of the same program, ostream::write and
istream::read are what you need.  Note, however, that this ony works 1)
in the same run of the same program, and 2) for PODs without pointers.

If you are writing something that will be read by another program, or a
later run of the same program, you'll have to define a specific format
to use, and implement streams to input and output that.  If you are
writing something that will be read by an existing program, or be
transmitted over a network to another machine, you will have to find out
what protocol is expected, and adher to it.

|>  Any public library?

Not that I know of.  I think that there is a library somewhere that
outputs in format RPC, or maybe some Internet format.

|>  What do you think about this choice?

What other choice is possible?  It's not reasonable to ask the standard
to support all binary formats, and it's not reasonable for it to favor
any one of them.  Given that, what else can you do.

--
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