Re: [Boost-users] [numeric conversation] behavior on std::numeric_limits<double>::max() + eps with numeric_cast

Subject: Re: [Boost-users] [numeric conversation] behavior on std::numeric_limits<double>::max() + eps with numeric_cast
From: Brandon Kohn (blkohn_at_[hidden])
Date: 2014-06-11 08:51:45

On 6/11/2014 07:06 AM, Olaf Peter wrote:
> Am 10.06.2014 18:28, schrieb Brandon Kohn:
>> I should note that in each of these specializations care must be taken
>> that bounds are properly checked given the context of the conversion
>> direction. In my test I essentially converted the fundamental type to an
>> instance of intrinsic_type (via the template constructor) and then used
>> that to compare with the bounds of the intrinsic_type<T>. In a real
>> world example this is possibly nonsense.
> 
> I thought this is what the checker does already, including test on NaN
> and Inf. Could you explain this?
> 
What I mean is that the range checker is checking the whether the values
in the source instance can be represented in the target instance. So one
must ensure that for a given conversion (like my_type -> int) a
range_checker type exists which can perform that check. Your original
checker did cover the types of checks needed, it just neglected to deal
with the interfaces on the respective types (source/target.) Apologies
if I'm stating the obvious.

Let me know if you have any more issues. I'm happy to help.

Cheers,

Brandon