Re: [Boost-users] [ICL] More compilation questions/problems

Subject: Re: [Boost-users] [ICL] More compilation questions/problems
From: Joachim Faulhaber (afojgo_at_[hidden])
Date: 2011-03-07 14:40:43

2011/3/7 John Reid <j.reid_at_[hidden]>:
> On 07/03/11 14:49, John Reid wrote:
>>
>> #include <boost/icl/interval.hpp>
>>
>> template< typename IntervalT >
>> void
>> check_contains() {
>> IntervalT interval;
>> typedef typename IntervalT::domain_type domain_t;
>> ::boost::icl::contains( interval, domain_t() );
>> }
>>
>> void h() {
>> namespace icl = ::boost::icl;
>> check_contains< icl::continuous_interval< float > >();
>> check_contains< icl::discrete_interval< int > >();
>> check_contains< icl::right_open_interval< float > >();
>> check_contains< icl::left_open_interval< float > >();
>> check_contains< icl::closed_interval< float > >();
>> check_contains< icl::open_interval< float > >();
>> }
>>
>>
>> The last 2 lines in h() do not compile whilst the preceeding 4 do. Is
>> this by design or a bug? Testing elements for membership of a closed or
>> open interval seems natural enough. I'm using gcc 4.4.3.
>>
>> Thanks,
>> John.
>
>
> Also operator== does not seem to work on closed and open intervals, e.g.
>
> icl::closed_interval< float >() == icl::closed_interval< float >()
>
> does not compile.

Hi John!

thanks for your thorough work on the many instances of ICL class
templates. The compilation failures of the current examples

icl::closed_interval< float >()
icl::open_interval< float >()

are by design again. The related information can be found in the docs
http://www.boost.org/doc/libs/1_46_0/libs/icl/doc/html/boost_icl/interface.html#boost_icl.interface.class_templates
in: Table 1.6. Usability of interval class templates for discrete or
continuous domain types.

The reason for this: All icl interval objects, that can be constructed
are supposed to work with interval containers. If I have an interval
set
{[0.0, 2.0]}
of a continuous domain type using statically bounded closed intervals
and I want to subtract another closed interval
{[0.0, 2.0]} - [1.0, 1.0]
I am unable to represent the result
{[0.0, 1.0),(1.0, 2.0]}
with the same kind of statically bounded interval.

Therefore I don't allow statically bounded closed and open intervals
(the symmetric interval types) to be instantiated with continuous
types.

Thanks again
Joachim

-- 
Interval Container Library [Boost.Icl]
http://www.joachim-faulhaber.de