[boost] [boost.test] Floating point comparison fails to compile with templated value type

From: Hugo Duncan (hugoduncan_at_[hidden])
Date: 2007-11-29 17:36:55

Hi,

I was wanting to check two boost::numeric::interval's for closeness, but  
find I get a compile error.  The below fails to compile, with the error  
messages shown.

I believe this is because
   i) the comparison operator for interval is templated,
  ii) boost.test wraps one of the values with a readonly_property
and therefore the template is not an exact match.  Changing the tolerance  
to an interval does not change anything.  This is with MSVC8 and with gcc  
3.4.4 on windows.

Is this a bug, a missing feature - or am I misusing BOOST_CHECK_CLOSE ?

#define BOOST_AUTO_TEST_MAIN
#include <boost/test/auto_unit_test.hpp>
#include <boost/test/floating_point_comparison.hpp>
#include "boost/numeric/interval.hpp"
#include "boost/numeric/interval/io.hpp"
using boost::unit_test::test_suite;

BOOST_AUTO_TEST_CASE(test_interval)
{
   boost::numeric::interval<double> v1=1;
   boost::numeric::interval<double> v2=1;
   BOOST_CHECK_CLOSE(v1,v2,1e-5);
}

c:\cygwin\home\duncan\boost\boost/test/floating_point_comparison.hpp(184)  
: error C2679: binary '<=' : no operator found which takes a right-hand  
operand of type 'const boost::unit_test::readonly_property<PropertyType>'  
(or there is no acceptable conversion)
         with
         [
             PropertyType=boost::numeric::interval<double>
         ]
         c:\cygwin\home\duncan\boost\boost/numeric/interval/interval.hpp(82):  
could be 'bool boost::numeric::interval<T>::operator <=(const  
boost::numeric::interval<T>::interval_holder &) const'
         with
         [
             T=double
         ]
         c:\cygwin\home\duncan\boost\boost/numeric/interval/interval.hpp(89):  
or 'bool boost::numeric::interval<T>::operator <=(const  
boost::numeric::interval<T>::number_holder &) const'
         with
         [
             T=double
         ]
         while trying to match the argument list  
'(boost::numeric::interval<T>, const  
boost::unit_test::readonly_property<PropertyType>)'
         with
         [
             T=double
         ]
         and
         [
             PropertyType=boost::numeric::interval<double>
         ]