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Groups > comp.lang.c++ > #11618
| From | Victor Bazarov <v.bazarov@comcast.invalid> |
|---|---|
| Newsgroups | comp.lang.c++ |
| Subject | Re: Mutability of temporary variables |
| Date | 2011-11-19 08:42 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <ja8bo7$88k$1@dont-email.me> (permalink) |
| References | <op.v4605gilpbcp0d@localhost.localdomain> |
On 11/19/2011 7:33 AM, kyle wrote:
> Consider following code:
>
> int main() {
> const int& c = int();
> int& m = const_cast<int&>(c);
> m = 4;
> }
>
> The object of the snippet is to get a mutable reference to a temporary.
> This cant be done directly because non-const reference cannot bind to
> temporary, but we should be OK with casting away constness of reference
> 'c' since it doesn't actually refer to const object.
>
> Temporaries are mutable, so in whole my snippet is legal C++. Am i correct?
AIUI, your code has undefined behavior. 'c' is bound to an rvalue, and
using 'const_cast' to produce an lvalue out of it is not among the
allowed operations for 'const_cast'.
V
--
I do not respond to top-posted replies, please don't ask
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Mutability of temporary variables kyle <kyle@nomail.com> - 2011-11-19 13:33 +0100
Re: Mutability of temporary variables Paavo Helde <myfirstname@osa.pri.ee> - 2011-11-19 07:18 -0600
Re: Mutability of temporary variables Victor Bazarov <v.bazarov@comcast.invalid> - 2011-11-19 08:45 -0500
Re: Mutability of temporary variables Leigh Johnston <leigh@i42.co.uk> - 2011-11-19 14:25 +0000
Re: Mutability of temporary variables "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-11-20 00:14 +0000
Re: Mutability of temporary variables Leigh Johnston <leigh@i42.co.uk> - 2011-11-20 00:45 +0000
Re: Mutability of temporary variables Leigh Johnston <leigh@i42.co.uk> - 2011-11-20 01:14 +0000
Re: Mutability of temporary variables "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-11-20 02:34 +0000
Re: Mutability of temporary variables "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-11-20 02:44 +0000
Re: Mutability of temporary variables Leigh Johnston <leigh@i42.co.uk> - 2011-11-20 13:06 +0000
Re: Mutability of temporary variables Leigh Johnston <leigh@i42.co.uk> - 2011-11-20 13:21 +0000
Re: Mutability of temporary variables "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-11-20 16:51 +0000
Re: Mutability of temporary variables Leigh Johnston <leigh@i42.co.uk> - 2011-11-20 17:24 +0000
Re: Mutability of temporary variables SG <s.gesemann@gmail.com> - 2011-11-20 00:49 -0800
Re: Mutability of temporary variables Victor Bazarov <v.bazarov@comcast.invalid> - 2011-11-19 08:42 -0500
Re: Mutability of temporary variables Paavo Helde <myfirstname@osa.pri.ee> - 2011-11-19 08:20 -0600
Re: Mutability of temporary variables Victor Bazarov <v.bazarov@comcast.invalid> - 2011-11-19 15:51 -0500
Re: Mutability of temporary variables Paavo Helde <myfirstname@osa.pri.ee> - 2011-11-19 16:51 -0600
Re: Mutability of temporary variables "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-11-20 00:23 +0000
Re: Mutability of temporary variables Johannes Schaub <schaub.johannes@googlemail.com> - 2011-11-19 16:16 +0100
Re: Mutability of temporary variables "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-11-20 00:31 +0000
Re: Mutability of temporary variables kyle <kyle@nomail.com> - 2011-11-24 00:50 +0100
Re: Mutability of temporary variables Johannes Schaub <schaub.johannes@googlemail.com> - 2011-11-24 20:36 +0100
Re: Mutability of temporary variables SG <s.gesemann@gmail.com> - 2011-11-21 01:17 -0800
Re: Mutability of temporary variables Johannes Schaub <schaub.johannes@googlemail.com> - 2011-11-22 23:26 +0100
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