Boost C++ Libraries: Ticket #7068: Compiler warnings in date_time

cc set

Tue, 03 Jul 2012 20:02:40 GMT

cc zhnmju123@… added

Marshall Clow — Tue, 03 Jul 2012 22:11:19 GMT

Ok. I looked at these warnings, and they are all bogus. For example, in int_adapter.hpp, we have:

72:    switch (sv) {
73:      case not_a_date_time: return not_a_number();
74:      case neg_infin:       return neg_infinity();
75:      case pos_infin:       return pos_infinity();
76:      case max_date_time:   return (max)();
77:      case min_date_time:   return (min)();
78:      default:              return not_a_number();
79:    }

which (apparently) gives an error of: C:\Program Files\C++\Boost\boost\date_time\int_adapter.hpp|75|warning: enumeration value 'not_special' not handled in switch [-Wswitch-enum]|

That's absurd. not_special is definitely handled here; it's spelled default.

conversion.hpp(33) - this problem.
int_adapter.hpp(75) - this problem.
time_system_counted.hpp(149) - this problem.

I suggest that you turn off this warning and report it as a bug against gcc.

status changed; resolution set

Marshall Clow — Wed, 01 Aug 2012 04:09:21 GMT

status new → closed
resolution → invalid

andrewtrapani@… — Sat, 12 Sep 2015 00:53:00 GMT

Hi,

I ran across this today and wanted to offer an opinion. In the example above by marshall, the default catches everything not listed and returns NaN.

Now if we add a new enum value "foobar", it will automatically return NaN. But what if we forgot to edit the above switch when we actually needed foobar to return foobar_value() as in some value other than NaN?

The flipside is now we are forcing the coder to write out all of the cases.

    switch (sv) {
      case not_a_date_time: return not_a_number();
      case neg_infin:       return neg_infinity();
      case pos_infin:       return pos_infinity();
      case max_date_time:   return (max)();
      case min_date_time:   return (min)();
      case foobar:          return foobar_value();
      case foo:
      case bar:
      case fizz:
      //and so on all fall into default or else we get a bunch of warnings
      default:              return not_a_number();
    }

It looks like this feature is not ready for usage unless something changes about the enum declaration options in newer C++ version.