Boost C++ Libraries: Ticket #11211: Fusion example no longer compiles (BOOST_FUSION_DEFINE_STRUCT)

attachment set

Mon, 20 Apr 2015 19:16:12 GMT

attachment → error.txt

severity, summary changed

Mon, 20 Apr 2015 19:26:27 GMT

severity Problem → Regression
summary Fusion example no longer compiles → Fusion example no longer compiles (BOOST_FUSION_DEFINE_STRUCT)

Joel de Guzman — Mon, 20 Apr 2015 19:44:18 GMT

confirmed clang and g++. i added this test case.

milestone changed; cc set

Tue, 21 Apr 2015 00:00:12 GMT

cc flast@… added
milestone To Be Determined → Boost 1.59.0

Confirmed.

Ah, I see, it's my bad.

The constructors of BOOST_FUSION_DEFINE_STRUCT (might other variations too) is not a template: the constructors of each elements must be constexpr.

damien.buhl@… — Tue, 21 Apr 2015 07:14:01 GMT

Sorry I didn't see you already handled the problem. I made a pull-request on github in between. It is ok for you or you wanted to do something finer ?

Joel de Guzman — Tue, 21 Apr 2015 07:26:57 GMT

I just added a test case, not a fix. Is there another PR? Anyway, I merged Damien's.

anonymous — Tue, 21 Apr 2015 07:28:32 GMT

I just added a test case, not a fix. Is there another PR? Anyway, I merged Damien's.

damien.buhl@… — Mon, 27 Apr 2015 08:30:04 GMT

I added another PR for BOOST_FUSION_DEFINE_INLINE_STRUCT and added some other test cases.

I thought for people who are using the library in version 1.58 right now they can work the issue around with : g++ -DBOOST_CONSTEXPR=

Tue, 28 Apr 2015 15:27:45 GMT

I thought for people who are using the library in version 1.58 right now they can work the issue around with : g++ -DBOOST_CONSTEXPR=

Unfortunately, this workaround doesn't work.

Wed, 29 Apr 2015 08:48:59 GMT

I think we should release some patches to fix this issue, like ttps://github.com/boostorg/website/blob/master/feed/history/boost_1_58_0.qbk#L25-L40 .

candidates

ttps://github.com/boostorg/fusion/pull/70
ttps://github.com/boostorg/fusion/pull/71

Mon, 04 May 2015 09:28:41 GMT

Here is another minimal test case that fails to compile (in c++11) but now using BOOST_FUSION_ADAPT_STRUCT. I suspect that it is the same issue.

#include <boost/fusion/adapted/struct.hpp>
struct X {};
BOOST_FUSION_ADAPT_STRUCT(
        X,
)
int main() {
        return 0;
}

Mon, 04 May 2015 14:48:24 GMT

Replying to Dennis Brentjes <d.brentjes@…>:

Here is another minimal test case that fails to compile (in c++11) but now using BOOST_FUSION_ADAPT_STRUCT. I suspect that it is the same issue.
#include <boost/fusion/adapted/struct.hpp>
struct X {};
BOOST_FUSION_ADAPT_STRUCT(
        X,
)
int main() {
        return 0;
}

No, it's not a same issue; you can test with -DBOOST_NO_CXX11_CONSTEXPR flag to disabling BOOST_CONSTEXPR feature.

In original test case, work with -DBOOST_NO_CXX11_CONSTEXPR due to avoiding regression: http://melpon.org/wandbox/permlink/APJ0Vi289gSKA7MO . However, your case dosn't work even defining -DBOOST_NO_CXX11_CONSTEXPR: http://melpon.org/wandbox/permlink/ktex1HEt5w4bplsv .

Tue, 05 May 2015 12:46:42 GMT

You are right. It seems it's related to adapting an empty struct. Something which was possible in 1.57. Should I create a separate ticket for this issue?

Tue, 05 May 2015 14:10:43 GMT

Replying to Dennis Brentjes <d.brentjes@…>:

Should I create a separate ticket for this issue?

Yes, please!

Joel, I think this issue is now fixed and can be closed.

status changed; resolution set

Joel de Guzman — Tue, 05 May 2015 19:32:43 GMT

status new → closed
resolution → fixed