[Boost-users] [chrono] bad use of constexpr (was: [1.52.0] Beta release candidates available)

Subject: [Boost-users] [chrono] bad use of constexpr (was: [1.52.0] Beta release candidates available)
From: Eric Niebler (eric_at_[hidden])
Date: 2012-10-05 13:08:53

On 10/5/2012 8:56 AM, Lemay.Steve wrote:
> Here's the first problem that pops up for me... QNXNTO gcc 4.7.1
> 
> qcc.compile.c++ D:\boostBuild_QCC_1_52_0_beta1\boost\bin.v2\libs\chrono\build\qcc\release\link-static\target-os-qnxnto\threadapi-pthread\threading-multi\chrono.o
> In file included from ./boost/chrono/chrono.hpp:11:0,
>                  from ./boost/chrono/detail/inlined/chrono.hpp:13,
>                  from libs\chrono\src\chrono.cpp:14:
> ./boost/chrono/duration.hpp: In static member function 'static constexpr float boost::chrono::detail::chrono_numeric_limits<float, true>::lowest()':
> ./boost/chrono/duration.hpp:355:56: error: call to non-constexpr function 'static std::numeric_limits<float>::_Ty std::numeric_limits<float>::max()'
> ./boost/chrono/duration.hpp: In static member function 'static constexpr double boost::chrono::detail::chrono_numeric_limits<double, true>::lowest()':
> ./boost/chrono/duration.hpp:363:57: error: call to non-constexpr function 'static std::numeric_limits<double>::_Ty std::numeric_limits<double>::max()'
> ./boost/chrono/duration.hpp: In static member function 'static constexpr long double boost::chrono::detail::chrono_numeric_limits<long double, true>::lowest()':
> ./boost/chrono/duration.hpp:371:61: error: call to non-constexpr function 'static std::numeric_limits<long double>::_Ty std::numeric_limits<long double>::max()'
> cc: d:/qnxsdk/qnxsdk6.5-001/host/win32/x86/usr/lib/gcc/i486-pc-nto-qnx6.5.0/4.7.1/cc1plus caught signal 1
> 
>     "QCC" -Wc,-ftemplate-depth-128 -DFD_SETSIZE=2048 -march=k8-sse3 -mtune=k8-sse3 -mmmx -msse3 -mfpmath=sse -mno-3dnow -mstackrealign -Wc,-fPIC,-std=c++0x,-std=gnu++0x -O3 -Wc,-finline-functions -Wc,-Wno-inline -Wc,-Wall -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "D:\boostBuild_QCC_1_52_0_beta1\boost\bin.v2\libs\chrono\build\qcc\release\link-static\target-os-qnxnto\threadapi-pthread\threading-multi\chrono.o" "libs\chrono\src\chrono.cpp"
> 
> ...failed qcc.compile.c++ D:\boostBuild_QCC_1_52_0_beta1\boost\bin.v2\libs\chrono\build\qcc\release\link-static\target-os-qnxnto\threadapi-pthread\threading-multi\chrono.o...
> common.copy D:\boost\include\boost\checked_delete.hpp
> D:\boost_1_52_0_beta1\boost\checked_delete.hpp
>         1 file(s) copied.
> common.copy D:\boost\include\boost\chrono.hpp
> D:\boost_1_52_0_beta1\boost\chrono.hpp
>         1 file(s) copied.
> qcc.compile.c++ D:\boostBuild_QCC_1_52_0_beta1\boost\bin.v2\libs\chrono\build\qcc\release\link-static\target-os-qnxnto\threadapi-pthread\threading-multi\process_cpu_clocks.o
> In file included from ./boost/chrono/process_cpu_clocks.hpp:18:0,
>                  from ./boost/chrono/detail/inlined/process_cpu_clocks.hpp:19,
>                  from libs\chrono\src\process_cpu_clocks.cpp:17:
> ./boost/chrono/duration.hpp: In static member function 'static constexpr float boost::chrono::detail::chrono_numeric_limits<float, true>::lowest()':
> ./boost/chrono/duration.hpp:355:56: error: call to non-constexpr function 'static std::numeric_limits<float>::_Ty std::numeric_limits<float>::max()'
> ./boost/chrono/duration.hpp: In static member function 'static constexpr double boost::chrono::detail::chrono_numeric_limits<double, true>::lowest()':
> ./boost/chrono/duration.hpp:363:57: error: call to non-constexpr function 'static std::numeric_limits<double>::_Ty std::numeric_limits<double>::max()'
> ./boost/chrono/duration.hpp: In static member function 'static constexpr long double boost::chrono::detail::chrono_numeric_limits<long double, true>::lowest()':
> ./boost/chrono/duration.hpp:371:61: error: call to non-constexpr function 'static std::numeric_limits<long double>::_Ty std::numeric_limits<long double>::max()'
> cc: d:/qnxsdk/qnxsdk6.5-001/host/win32/x86/usr/lib/gcc/i486-pc-nto-qnx6.5.0/4.7.1/cc1plus caught signal 1

For the record, I hit the same thing recently. In my case, it was a
recently built clang that picked up an older libstdc++. The trouble is,
just because a compiler supports constexpr doesn't mean the standard
library does. Chrono doesn't seem to be making that distinction.

It would be great to get this fixed for final release.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com