This is the mail archive of the libstdc++@gcc.gnu.org mailing list for the libstdc++ project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: Movables in std::vector

From: Paolo Carlini <paolo dot carlini at oracle dot com>
To: Magnus Fromreide <magfr at lysator dot liu dot se>
Cc: libstdc++ at gcc dot gnu dot org
Date: Wed, 12 Oct 2011 22:54:09 +0200
Subject: Re: Movables in std::vector
References: <1318452486.1986.10.camel@sara>

On 10/12/2011 10:48 PM, Magnus Fromreide wrote:

Hello.
Using trunk and c++0x-mode I tried to use a vector of a movable, but not
copyable, type.
That failed.

Looking inside stl_vector.h I find the following code line:

__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
and that seems to indicate that movable types aren't yet allowed in
vectors. Is that intentional?

Those concept-checks are very-very old and haven't been updated for C++11. If you ask me, I suspect they will never be, frankly, unless somebody volunteers, and still, the whole technology is rather weak if assessed today, after all the serious work on real Concepts, there are some subtle cases that simply you can't get right with that approach. Thus, sorry, just don't use -D_GLIBCPP_CONCEPT_CHECKS together with -std=c++0x/gnu++0x.

Paolo.

References:
- Movables in std::vector
  - From: Magnus Fromreide

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]