Re: [boost] [function] boost::function<>::swap() can throw

From: Niels Dekker - mail address until 2008-12-31 (nd_mail_address_valid_until_2008-12-31_at_[hidden])
Date: 2008-02-22 04:56:26

Arvid Norberg wrote:
> I was quite surprised to realize that boost::function<>::swap can
> throw in case a memory allocation fails.
> Is this intentional or a known issue?
>
> The TR1 function<>::swap is specified not to throw.

Pete Becker once explained at comp.std.c++:
> [requiring a non-throwing swap] precludes a small-object optimization
> for std::tr1::function. If its swap member function is allowed to 
> throw
> exceptions then it can hold small function objects internally rather
> than putting them on the free store

Please check out the discussion at comp.std.c++, September 2006, Re: Is 
a Swappable class allowed to throw an exception?
http://groups.google.com/group/comp.std.c++/browse_thread/thread/4e20e4329345e00b/0bc45728617b6938#0bc45728617b6938

Still I would appreciate having a non-throwing swap for 
boost::function...  But at least the Standard and the Boost library 
should be in sync!  Are you going to make a ticket on this issue?

Kind regards,
-- 
Niels Dekker
http://www.xs4all.nl/~nd/dekkerware
Scientific programmer at LKEB, Leiden University Medical Center