This may be a somewhat newbie question.

This is cross-posted on stack exchange before I found this list.

(https://stackoverflow.com/questions/51062374/different-behavior-with-enable-if-using-clang-and-g)

I'm having trouble compiling the following piece of boost-based code:

*****

#include <boost/numeric/interval.hpp>

#include <complex>

int main(){

std::complex<boost::numeric::interval<double> > my_interval(1,1);

my_interval *= my_interval;

return 0;}

*****

When I compile using g++ (MacPorts gcc5 5.5.0_1), I get no compilation errors (g++ -std=c++14 main.cpp).

When I compile using clang++ (Apple LLVM version 8.1.0 (clang-802.0.38)), I get compilation errors (clang++ -std=c++14 main.cpp).

Summarizing the error, it appears that an enable_if in cmath (line 424: std::enable_if<std::is_arithmetic<_A1>::value, bool>::type) is preventing isnan from being defined for boost::numeric::interval<double> (at least in clang++).

Am I doing something wrong or is there a work around? I realize that this might be more of a std::complex question than a boost question, but since it involves boost, I thought that I'd ask here.

Thank you. The full and complete error is below.

*****

Full and Complete Error:

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:599:9: error:

no matching function for call to 'isnan'

if (isnan(__x) && isnan(__y))

^~~~~

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/complex:312:27: note:

in instantiation of function template specialization

'std::__1::operator*<boost::numeric::interval<double,

boost::numeric::interval_lib::policies<boost::numeric::interval_lib::rounded_math<double>,

boost::numeric::interval_lib::checking_strict<double> > > >' requested

here

*this = *this * complex(__c.real(), __c.imag());

main.cpp:6:15: note: in instantiation of function template specialization

'std::__1::complex<boost::numeric::interval<double,

boost::numeric::interval_lib::policies<boost::numeric::interval_lib::rounded_math<double>,

boost::numeric::interval_lib::checking_strict<double> > >

>::operator*=<boost::numeric::interval<double,

boost::numeric::interval_lib::policies<boost::numeric::interval_lib::rounded_math<double>,

boost::numeric::interval_lib::checking_strict<double> > > >' requested

here

my_interval *= my_interval;

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/cmath:424:25: note:

candidate template ignored: disabled by 'enable_if' [with _A1 =

boost::numeric::interval<double,

boost::numeric::interval_lib::policies<boost::numeric::interval_lib::rounded_math<double>,

boost::numeric::interval_lib::checking_strict<double> > >]

typename std::enable_if<std::is_arithmetic<_A1>::value, bool>::type