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

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::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::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::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::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::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::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