Re: Vector exception safety
on Sat Jul 21 2007, Aarti <aarti.sanga-AT-gmail.com> wrote:
I was reading about exception safety in vectors and came across a
statement that says
The clear operation of vector guarantees a nothrow provided the copy
and assignment operator do not throw an exception.
Now clear just deletes all the elements of a vector. What has copy
and assignment operator got to do with it?
Can anyone please shed some light?
It's really a side-effect of the specification. In practice it will
never throw. The problem is that clear() is specified in terms of
erase(), and in the general case, erase must be able to move elements.
Probably the right fix is to move this statement from 23.1.3.1 into
23.1, without the initial qualification about unordered associative
containers.
23.1.3.1 Exception safety guarantees [unord.req.except]
For unordered associative containers, no clear() function
throws an exception.
Howard, can you put this on the issues list?
Thanks,
--
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com
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