error C2668: 'fpclassify' : ambiguous call to overloaded function

error C2668: “fpclassify”: 对重载函数的调用不明确

error C2668: 'fpclassify' : ambiguous call to overloaded function

Hey Guys,
first a big thank you to all the developers, you are doing a really great job.
And a big thanks to the people who made lux compiling on windows again. (At least for me ).
Sadly the revision 2364 breaks compiling of LibSLG for me.
Visual Studio 2013 Ultimate says "Error 494 error C2668: 'isinf' : ambiguous call to overloaded function (..\..\..\..\..\luxrays\src\slg\film\film.cpp)" and brings this error quite a few times in "luxrays\src\slg\film\film.cpp" and "luxrays\src\slg\sdl\texture.cpp"

I investigated it further and found that at least my compiling environment needs in Release Mode (the only one I tested) this code block in luxrays/core/utils.h

#if defined(WIN32)
#define isinf(f) (!_finite((f)))
#else
using std::isinf;
#endif


to compile LibSLG succesfully.
I have attached a patch with the change so that you can have a look at it.