Re: [boost] Checked Integral Class

From: Rob Stewart (stewart_at_[hidden])
Date: 2005-09-16 17:58:06

From: "michael toksvig" <michaeltoksvig_at_[hidden]>
> 
> matt, i don't think your code example disambiguates what rob and i are 
> disagreeing on
> 
> when you say:
> > MyCv c = a + b; // Should fail
> 
> you don't say why you think it should fail. there are (at least) 3 
> possibilities:
> a) at compile time (because it is an error to try to assign a 0-20 number to 
> a 0-10 number)
> b) at runtime, during the assignment (because it is an error to assign a 
> 0-20 number to a 0-10 number if it is outside the 0-10 range)
> c) at runtime, during the addition (because it is an error to add two 0-10 
> numbers if they add up to more than 10)
> 
> i think a) and b) are both useful, and i think rob is advocating c)

Yes, but using a checking policy, you can have all three, though
I'm not sure how to express the difference between a) and c).
"compile_time_check" and "run_time_check" are insufficient.  You
might need separate policies to dictate how conversions and
operations are checked.

-- 
Rob Stewart                           stewart_at_[hidden]
Software Engineer                     http://www.sig.com
Susquehanna International Group, LLP  using std::disclaimer;