Re: [boost] [system] Clang CI builds broken because of constexpr

Subject: Re: [boost] [system] Clang CI builds broken because of constexpr
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2018-07-20 11:39:07

On 07/20/18 14:16, Peter Dimov via Boost wrote:
> Andrey Semashev wrote:
>> Hi,
>>
>> I'm seeing these errors in Travis CI builds with Clang 3.8, 3.9, 4.0 
>> and 5.0:
>>
>> ./boost/system/error_code.hpp:232:41: error: constexpr constructor 
>> never produces a constant expression [-Winvalid-constexpr]
>> Â Â Â Â Â Â Â Â  BOOST_SYSTEM_CONSTEXPR explicit std_category( 
>> boost::system::error_category const * pc ): pc_( pc )
>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â  ^
>> ./boost/system/error_code.hpp:232:41: note: non-constexpr constructor 
>> 'error_category' cannot be used in a constant expression
>> /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/system_error:69:5: 
>> note: declared here
>> Â Â Â Â  error_category() noexcept;
>> Â Â Â Â  ^
>>
>> I'm assuming this is because the compiler uses libstdc++ from gcc 4.8, 
>> in which error_category() is not marked constexpr. Can this be fixed 
>> somehow?
> 
> This should be fixed now in develop; will merge to master if Marshall 
> gives me permission.

Thanks, Peter. Will re-run my CI builds.