Re: [Patch] stl_vector.h

[Paolo Carlini <pcarlini at suse dot de>]

Dhruv Matani wrote:

> Hello,
> 	Here is the patch for the bug that I had mentioned earlier on.
>
> I ahve also attached a test-case for replicating the bug.
>
> This bug actually helped me fix a totally unralated error in some other
> part of my program!
>  
I don't think we have a bug, neither I think your testcase is correct. 
Why you have an assert( n != 0) in the allocator? According to the 
standard, the return value of allocate when n == 0 is unspecified, 
indeed, but is anyway perfectly legal to call allocate with n == 0. What 
happens then in std::vector is that all of the _M_impl pointers become 
equal and the  various algorithms do not iterate at all, no problem. In 
fact all of our allocators + vector accept std::vector vv(0, 1) and are 
able to deal with it correctly subsequently. To summarize, I think that 
the testcase (the allocator part of it) is wrong, not our vector class.

Paolo.