[Boost-bugs] [Boost C++ Libraries] #3342: vector_c should use maximum integral constant type

Subject: [Boost-bugs] [Boost C++ Libraries] #3342: vector_c should use maximum integral constant type
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-08-14 06:21:21

#3342: vector_c should use maximum integral constant type
------------------------------------------------------+---------------------
 Reporter:  Maxim Yanchenko <Maxim.Yanchenko@…>       |       Owner:  agurtovoy
     Type:  Bugs                                      |      Status:  new      
Milestone:  Boost 1.40.0                              |   Component:  mpl      
  Version:  Boost 1.39.0                              |    Severity:  Problem  
 Keywords:                                            |  
------------------------------------------------------+---------------------
 It looks like currently long is built in, which leads to problems on 32
 bit architectures with sizeofs int = long < int64_t.

 How it's defined currently:
 {{{
 #!cpp
 template<
       typename T, long C0 = LONG_MAX, long C1 = LONG_MAX, long C2 =
 LONG_MAX, ...
     >
 struct vector_c;
 }}}


 I believe the maximum integral type (e.g. int64_t) should be used instead
 of long.

 Example that shows the problem:
 {{{
 #!cpp
   const int64_t max_int         = integer_traits<int>::const_max;
   const int64_t max_int_plus_1  = max_int + 1;

   BOOST_MPL_ASSERT(( equal<           vector_c< int64_t, 1 >
                           , vector< integral_c< int64_t, 1 > >
                           > ));

   BOOST_MPL_ASSERT(( equal<           vector_c< int64_t, max_int >
                           , vector< integral_c< int64_t, max_int > >
                           > ));

   BOOST_MPL_ASSERT(( equal<           vector_c< int64_t, max_int_plus_1 >
                           , vector< integral_c< int64_t, max_int_plus_1 >
 >
                           > ));
 }}}
 The first assert passes, while the second and third fail with the
 following
 error messages (removed repetition of 2147483647l for readability):
 {{{
 test.h:149: error: ************mpl::equal<mpl::vector_c<int64_t,
 2147483647l,
 2147483647l, ...>, mpl::vector<mpl_::integral_c<int64_t, 2147483647>>,
 is_same<true> >::************'
 test.h:153: error: ************mpl::equal<mpl::vector_c<int64_t,
 -0x00000000080000000l, 2147483647l, ...>,
 mpl::vector<mpl_::integral_c<int64_t,
 2147483648ll>>, is_same<true> >::************'
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3342>
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