[Bug libstdc++/53840] New: [C++11] DR 921. Rational Arithmetic should use template aliases

[Bug libstdc++/53840] New: [C++11] DR 921. Rational Arithmetic should use template aliases

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53840

             Bug #: 53840
           Summary: [C++11] DR 921. Rational Arithmetic should use
                    template aliases
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: redi@gcc.gnu.org


http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3358.html#921

This should compile:

  #include <chrono>
  std::chrono::duration<long, std::ratio_divide<std::kilo, std::milli>> d;


/home/jwakely/gcc/4.x/include/c++/4.8.0/chrono:227:2: error: static assertion
failed: period must be a specialization of ratio
  static_assert(__is_ratio<_Period>::value,
  ^

The obvious implementation would be to rename each ratio_xxx class template to
__ratio_xxx then add:

template<typename _R1, typename _R2>
  using ratio_xxx = typename __ratio_xxx<_R1, _R2>::type;

[Bug libstdc++/53840] [C++11] DR 921. Rational Arithmetic should use template aliases

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53840

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-07-03
         AssignedTo|unassigned at gcc dot       |paolo.carlini at oracle dot
                   |gnu.org                     |com
   Target Milestone|---                         |4.8.0
     Ever Confirmed|0                           |1

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-07-03 16:27:30 UTC ---
Can do this now.

[Bug libstdc++/53840] [C++11] DR 921. Rational Arithmetic should use template aliases

[paolo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53840

--- Comment #2 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2012-07-03 19:24:15 UTC ---
Author: paolo
Date: Tue Jul  3 19:24:07 2012
New Revision: 189239

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=189239
Log:
2012-07-03  Paolo Carlini  <paolo.carlini@oracle.com>

    PR libstdc++/53840
    * include/std/ratio (ratio_multiply, ratio_divide, ratio_add,
    ratio_subtract): Use template aliases.
    * include/std/chrono (duration<>::duration(const duration<>&),
    duration_cast): Adjust.
    * testsuite/20_util/ratio/operations/53840.cc: New.
    * testsuite/20_util/duration/requirements/typedefs_neg1.cc: Adjust.
    * testsuite/20_util/duration/requirements/typedefs_neg2.cc: Likewise.
    * testsuite/20_util/duration/requirements/typedefs_neg3.cc: Likewise.
    * testsuite/20_util/ratio/operations/ops_overflow_neg.cc: Likewise.

Added:
    trunk/libstdc++-v3/testsuite/20_util/ratio/operations/53840.cc
Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/std/chrono
    trunk/libstdc++-v3/include/std/ratio
    trunk/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg1.cc
    trunk/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg2.cc
    trunk/libstdc++-v3/testsuite/20_util/duration/requirements/typedefs_neg3.cc
    trunk/libstdc++-v3/testsuite/20_util/ratio/operations/ops_overflow_neg.cc

[Bug libstdc++/53840] [C++11] DR 921. Rational Arithmetic should use template aliases

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53840

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-07-03 19:25:13 UTC ---
Done.