How to use make command - c++

Question

I am trying to install this library :
https://github.com/sfdodge/xnet
I have successfully installed xtensor and xtensor blas using conda. Now, when I make this library (as mentioned in read me), it generates the following error:
CMakeFiles/test_xNet.dir/build.make:62: recipe for target 'CMakeFiles/test_xNet.dir/src/FullLayer.cpp.o' failed
make[2]: *** [CMakeFiles/test_xNet.dir/src/FullLayer.cpp.o] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/test_xNet.dir/all' failed
make[1]: *** [CMakeFiles/test_xNet.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
Edit:
Error:
In file included from /home/fatima/anaconda2/gcc/include/c++/string:48:0,
from /home/fatima/Downloads/xnet-master/src/FullLayer.hpp:4,
from /home/fatima/Downloads/xnet-master/src/FullLayer.cpp:1:
/home/fatima/anaconda2/gcc/include/c++/bits/stl_function.h:158:12: error: provided for ‘template<class _Tp> struct std::multiplies’
struct multiplies : public binary_function<_Tp, _Tp, _Tp>
^
In file included from /home/fatima/Downloads/xnet-master/src/mat.hpp:5:0,
from /home/fatima/Downloads/xnet-master/src/FullLayer.hpp:6,
from /home/fatima/Downloads/xnet-master/src/FullLayer.cpp:1:
/home/fatima/anaconda2/include/xtensor/xsort.hpp: In function ‘auto xt::sort(const xt::xexpression<E>&, std::ptrdiff_t)’:
/home/fatima/anaconda2/include/xtensor/xsort.hpp:190:43: error: ‘decay_t’ is not a member of ‘std’
return detail::flat_sort_impl<std::decay_t<decltype(de)>, eval_type>(de);