From: corey taylor <corey.taylor@gmail.com>
To: gkajmowi@tbaytel.net
Cc: gcc-help@gcc.gnu.org
Subject: Re: Problems with temporaries and C++ spec
Date: Sun, 28 Aug 2005 04:45:00 -0000 [thread overview]
Message-ID: <2e393d08050827214525510965@mail.gmail.com> (raw)
In-Reply-To: <200508271604.35552.gkajmowi@tbaytel.net>
Why are you using a private copy constructor there in the first place?
corey
On 8/27/05, Garrett Kajmowicz <gkajmowi@tbaytel.net> wrote:
> I'm working on my own C++ library for embedded applications (cxx.uclibc.org)
> and while implementing valarray I came across a problem with private copy
> contructors. The following code works in GCC 3.3.5, but not in GCC 3.4.2
>
> #include <iostream>
>
> class copy_to;
>
> class hidden_copying{
> public:
> friend class copy_to;
> friend class copy_from;
>
> private:
> hidden_copying() : q(0) { }
> hidden_copying(const hidden_copying &);
> hidden_copying & operator=(const hidden_copying &);
> int q;
> };
>
> class copy_to{
> public:
> friend class copy_from;
> copy_to() : p (0) { }
> copy_to(const hidden_copying & h) : p(h.q) { }
> int getval() const{
> return p;
> }
> private:
> int p;
> };
>
> class copy_from{
> public:
> friend class hidden_copying;
> copy_from() : r(0) { }
> copy_from(const int i) : r(i) { }
> copy_from(const copy_from & f) : r(f.r) { }
> hidden_copying data() const{
> hidden_copying retval;
> retval.q = r;
> return retval;
> }
>
> private:
> int r;
> };
>
>
> int main(){
> copy_from a(5);
> copy_to b(a.data());
> std::cout << "Value of copy_to: " << b.getval() << std::endl;
> return 0;
> }
>
> With gcc 3.4.2 I receive the following error message:
> ../temporarytest.cpp: In function `int main()':
> ../temporarytest.cpp:12: error: `hidden_copying::hidden_copying(const
> hidden_copying&)' is private
> ../temporarytest.cpp:48: error: within this context
>
> Without breaking valarray spec (in the above case, amounting to making any of
> the copy constructors of hidden_copying public), how can I get the above code
> work work properly. If There is no way, than please explain how to
> reconsile behaviors with spec definition of std::slice_array.
>
> Thank you for your help.
>
> - Garrett
>
prev parent reply other threads:[~2005-08-28 4:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-27 20:01 Garrett Kajmowicz
2005-08-28 4:45 ` corey taylor [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2e393d08050827214525510965@mail.gmail.com \
--to=corey.taylor@gmail.com \
--cc=gcc-help@gcc.gnu.org \
--cc=gkajmowi@tbaytel.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).