Re: [boost] [pool] Warnings in MSVC 7.1 and 8.0

From: JOAQUIN LOPEZ MU?Z (joaquin_at_[hidden])
Date: 2006-12-02 11:42:01

----- Mensaje original -----
De: Oleg Abrosimov <olegabr_at_[hidden]>
Fecha: Sábado, Diciembre 2, 2006 5:21 pm
Asunto: Re: [boost] [pool] Warnings in MSVC 7.1 and 8.0
Para: boost_at_[hidden]

> JOAQUIN LOPEZ MU?Z wrote:
> > 
> > Oleg, looks like Harmut Kaiser has already fixed this
> > problem in the CVS version of pool.hpp. Would you mind
> > downloading this newer version from
> > 
> > 
> 
http://boost.cvs.sourceforge.net/*checkout*/boost/boost/boost/pool/pool>
 .hpp?revision=1.15
> > 
> > and reporting whether the warnings you had go away?
> 
> I've examined it and found the following code snippet:
> 
> template <typename UserAllocator>
> void * pool<UserAllocator>::ordered_malloc(const size_type n)
> {
>   const size_type partition_size = alloc_size();
>   const size_type total_req_size = n * requested_size;
>   const size_type num_chunks = total_req_size / partition_size +
>       static_cast<bool>(total_req_size % partition_size);
> 
> 
> It suggests that warnings would persist.

Better than guessing, please try this version on your local
environment: do warnings still show up? After all, the change was
labeled by Harmut like "Removed VC7.1 warning 4800", so
it's reasonable to explicitly verify whether they make a
difference.

> 
> The problem is that this lines are copy-pasted in three different 
> places and it is a maintainability issue that Harmut Kaiser was
> catched by.
> 
> Second, he replaced this code in two other places by the following:
> 
>       const size_type partition_size = alloc_size();
>       const size_type total_req_size = n * requested_size;
>       const size_type num_chunks = total_req_size / 
> partition_size +
>           ((total_req_size % partition_size) ? true : false);
> 
> 
> I failed to see how it is better then original version, because 
> the 
> problem is in implicit conversion from bool to integer type during 
> promotion in operator+

As I said above, there must be a reason for Harmut to have committed
such changes, only actually trying this version will tell for sure.

Let's do the following: please try v1.15 of pool.hpp on your
local environment and check if the warnings persist or not: if the
former, please post a .diff between v1.15 and your proposed
modification and I can see that it makes it to the CVS next
Monday. How does this look yo you?

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo