Re: [boost] updated version of safe integer library

Subject: Re: [boost] updated version of safe integer library
From: Robert Ramey (ramey_at_[hidden])
Date: 2016-02-04 11:45:56

On 2/4/16 1:08 AM, Raphaël Londeix wrote:
>>
>> The problem with this is that the usage of safe<int> changes the meaning
>> of the program.
>>
>> int i; // i not initialized
>> ....   // program has weird behavior
>>
>
> In this particular case, the fact that the program was relying on UB means
> that the program had no meaning at all. So it adds a meaning maybe :)
>
> However I see your point ; you expect people to do something like:
>
> #ifdef DEBUG
> typedef safe<int> my_int;
> #else
> typedef int my_int;
> #endif
>

Note that the safe<T> is really safe<T, exception_policy = default_ep, 
promotion_policy = default_pp>.  there are several policies of each kind 
to choose from.  One of the exception policies is ignore - but I don't 
think it currently actually works.

What I actually expect is:

a) some wierd bug can't be found.
b) in desperation some intern just replaces all the ints with
safe<T>
c) problem is discovered - the safe... stuff is backed out and everyone 
(who is old enough) has a beer to congratulate themselves on how smart 
they are and the product is shipped.
d) In some cases, someone might unintentionally leave the safe stuff in 
- since shipping is already way overdue.
e) Or maybe some crusty old geezer who is tired of fixing this stuff 
after doing 50 times will game the system by doing:

i) change all the int... to my_safe<int>
ii) insert

template<typename T>
using my_safe<T> = safe<T>;

then in one place in the program he can switch settings for all his 
integer types - without using macros.

It's also possible I could use policies to optionally include 
initialization checking - which I see as relatively expensive.

Robert Ramey