Isnan

[Andreas Enge]

Hello,

has anyone followed what the deal is with isnan in core-updates? A number
of C++ packages does not build any more. For instance, dealii:
solver_control.cc:96:24: error: ‘isnan’ was not declared in this scope
       isnan(check_value) ||
                        ^
[ 30%] Building CXX object 
source/lac/CMakeFiles/obj_lac.debug.dir/solver_control.cc.o
cd /tmp/guix-build-dealii-8.2.1.drv-0/build/source/lac && 
/gnu/store/frrj3bfbmg5vrd0flh9cf8j64h7cr2v4-gcc-4.9.3/bin/c++   -DDEBUG 
-I/tmp/guix-build-dealii-8.2.1.drv-0/build/source/lac 
-I/tmp/guix-build-dealii-8.2.1.drv-0/build/include 
-I/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/include 
-I/gnu/store/pzk986yikywnql4x393pbhzbiz7vl72n-bzip2-1.0.6/include 
-I/gnu/store/f51hs67f3g1r15fy9xq4bi7m3z991p0j-tbb-4.3.2/include 
-I/gnu/store/5992iq1v7arqa14ym3di58n4la0893nv-zlib-1.2.8/include 
-I/gnu/store/5qp29kq39b23w0sb1306fhsrq0zfm6sl-suitesparse-4.4.3/include 
-I/gnu/store/693zbcqs6jv8zg7k1x8x8k3sm7fimqs0-boost-1.60.0/include 
-I/gnu/store/8vqdr67rfbxk12bl3gajshkiffn8l9ld-muparser-2.2.5-2/include  
-pedantic -fpic -Wall -Wpointer-arith -Wwrite-strings -Wsynth -Wsign-compare 
-Wswitch -Wno-unused-local-typedefs -Wno-long-long -Wno-deprecated 
-Wno-deprecated-declarations -fopenmp-simd -std=c++11 -Og -ggdb 
-Wa,--compress-debug-sections -o 
CMakeFiles/obj_lac.debug.dir/solver_control.cc.o -c 
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/source/lac/solver_control.cc
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/source/lac/solver_control.cc: 
In member function ‘virtual dealii::SolverControl::State 
dealii::SolverControl::check(unsigned int, double)’:
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/source/lac/solver_control.cc:96:24:
 error: ‘isnan’ was not declared in this scope
       isnan(check_value) ||
                        ^
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/source/lac/solver_control.cc:96:24:
 note: suggested alternative:
In file included from 
/gnu/store/frrj3bfbmg5vrd0flh9cf8j64h7cr2v4-gcc-4.9.3/include/c++/complex:44:0,
                 from 
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/include/deal.II/base/numbers.h:22,
                 from 
/tmp/guix-build-dealii-8.2.1.drv-0/build/include/deal.II/base/config.h:579,
                 from 
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/include/deal.II/base/logstream.h:19,
                 from 
/tmp/guix-build-dealii-8.2.1.drv-0/dealii-8.2.1/source/lac/solver_control.cc:16:
/gnu/store/frrj3bfbmg5vrd0flh9cf8j64h7cr2v4-gcc-4.9.3/include/c++/cmath:632:5: 
note:   ‘std::isnan’
     isnan(_Tp __x)

Apparently the "std::" is missing in front of "isnan"; should this not be 
implicit?

Andreas