Re: ostream::write

James Kanze <>
Tue, 5 May 2009 00:24:48 -0700 (PDT)
On May 4, 9:44 am, Ralf Goertz
<> wrote:

James Kanze wrote:

On May 3, 6:22 pm, Ralf Goertz

Now I am even more confused. How am I supposed to write an object of
type Foo to a file? I know about serialization, but sometimes one
needs to write something like an array of 10 unsigned 32 bit

You "serialize" it. Regardless of the object type, you
define a format (or adopt an existing format, like XDR),
then implement code to read and write that format.

But that brings me to my original question. If I serialize the
members using 'htonl' and friends I still end up with binary
data addresses /not/ in char* format for which I would need a
reinterpret_cast for writing. XDR seems to offer a char*, but
still I don't get why I need a cast for a perfectly portable
network representation of a long int.

Who said anything about using htonl? htonl is a hack, which
works on a few systems, but isn't generally applicable. Even
where it's applicable, it isn't without problems, e.g. alignment
questions. And there are protocols which use different
representations than what htonl would give, where it is
available. Define your format, then implement it. It's really
not that difficult for integer types. And that way, you know
what you've got.

James Kanze (GABI Software)
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