Boost C++ Libraries: Ticket #5598: boost/property_tree/detail/json_parser_write.hpp:35: warning: comparison is always true due to limited range of data type

Sebastian Redl — Tue, 07 Jun 2011 17:28:26 GMT

Ch might be wchar_t.

The warning can be suppressed by casting to some large integer type first, but I feel that the warning here is overeager and a bug.

Tue, 07 Jun 2011 17:38:37 GMT

Sorry, I was stating that in my case, Ch was char. Yes, it could be wchar_t as well. However, in the case of Ch being char, the warning is correct.

anonymous — Mon, 09 Jan 2012 17:53:01 GMT

Please create a comparison function for wide characters and specialize for Ch=char or unsigned char to not perform the comparison *b <= 0xff.

Thanks.

attachment set

Wed, 20 Jun 2012 18:12:30 GMT

attachment → json_parser_write.hpp.diff

Silence the warning from GCC about a comparison that is always true due to to the limits of the type by creating specializations of the check for char and unsigned char.

cc set

Thu, 28 Jun 2012 14:52:57 GMT

cc mika.fischer@… added

attachment set

Tue, 25 Jun 2013 22:19:12 GMT

attachment → json_parser_write.hpp.2.diff

Updated patch for 1.53.0

Tue, 25 Jun 2013 22:27:37 GMT

@Shane

I attached an updated version of the patch to this tracker.

However, the patch fails on my project because I had a double include of <boost/property_tree/json_parser.hpp> in two different compilation units. This caused my program build to fail due to a multiple definition for the check_is_ascii method. I created a simple test case that can be used to reproduce/debug the problem, I can send it to you if you want to.

If I have a time, I will check how this could be solved. For now, I just ensured that the json_parser.hpp file is included only once in my codebase.

Expect for this, your patch seems to work like a charm. Will report back if I find any problem with it.

Regards, Matt

cc changed

Mateusz Loskot — Thu, 18 Jul 2013 09:04:07 GMT

cc mateusz@… added

mk.boost@… — Wed, 24 Jul 2013 20:34:21 GMT

Replying to mloskot: I think, for explicitly instantiated template functions keyword 'inline' would fix the problem

Fri, 04 Oct 2013 14:33:14 GMT

Replying to Matthieu Vachon <matthieu.o.vachon@…>: Any chance you've tried out adding 'inline' as suggested in 7?

Also, will this change make it into 1.55.0?

chamara — Tue, 14 Jul 2015 08:16:23 GMT

Can you confirm what version this fix is going to go in?

attachment set

shane.turner@… — Tue, 08 Dec 2015 20:26:25 GMT

attachment → json_parser_write.hpp

Updated patch for 1.59.0

shane.turner@… — Mon, 28 Mar 2016 19:08:33 GMT

As of Boost 1.61.0 Beta 1 RC2, the file has changed from boost/property_tree/detail/json_parser_write.hpp to boost/property_tree/json_parser/detail/write.hpp

anonymous — Tue, 04 Jul 2017 03:44:34 GMT

In 1.64.0, the issue happens again, the fix in json_parser_write.hpp.2.diff is lost.