Re: [boost] [chrono] Dependency on math?

Subject: Re: [boost] [chrono] Dependency on math?
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2015-01-09 17:06:13

Le 09/01/15 20:03, Beman Dawes a écrit :
> On Fri, Jan 9, 2015 at 1:53 PM, John Maddock <boost.regex_at_[hidden]> wrote:
>>>> The latest dependency report shows chrono as having a dependency on math.
>>>
>>> chrono's dependency on math is only for common_factor_rt.hpp:
>>>
>>> http://www.pdimov.com/tmp/report-develop-3b5a9f4/chrono.html#math
>>>
>>> common_factor_rt.hpp and the accompanying _ct.hpp appear to belong to
>>> Integer. This actually seems a low-hanging fruit; these files are even
>>> authored by Daryle Walker et al, and Daryle is, I believe, the original
>>> author of Integer. Not clear how they ended up in Math.
>>
>> They were there already when Paul and I staged a coup ;)
>>
>> But yes they could be moved into integer relatively easily.
> While I certainly don't want you and Paul to "hack [math] apart in a
> hurry", moving those two headers to integer would seem to make more
> sense than asking Vicente to duplicate code in chrono.
>
>
There is a suplementaty issue. The dependencies of Chrono on Math 
wouldn't be broken as Chrono -> Ratio -> Rational -> Math
I would like to broke the Ratio -> Rational dependency (but this 
wouldn't be backward compatible). I think I added too much to Ratio, and 
that the Ratio -> rational conversion (in the same line than 
integral_constant -> Integral conversion) should be available via a free 
function (which obviously could not be implicit). In this case I could 
add the function in a Ratio.RationalConversion submodule (in the sens of 
a directory). I have this on my todo list, but I had not found yet the 
time to discuss the possibility of this breaking change. If you think 
this could be a good thing I could see when I can do it.

Best,
Vicente