Error(s):

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(20): error C2672: 'operator __surrogate_func': no matching overloaded function found
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(30): note: see reference to function template instantiation '_Ty std::_Accumulate<_Iter,_Ty,_Fn2>(_InIt,_InIt,_Ty,_Fn2)' being compiled
        with
        [
            _Ty=int,
            _Iter=N::C *,
            _Fn2=std::plus<void>,
            _InIt=N::C *
        ]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(38): note: see reference to function template instantiation '_Ty std::accumulate<_InIt,_Ty,std::plus<void>>(_InIt,_InIt,_Ty,_Fn2)' being compiled
        with
        [
            _Ty=int,
            _InIt=N::C *,
            _Fn2=std::plus<void>
        ]
source_file.cpp(8): note: see reference to function template instantiation '_Ty std::accumulate<N::C*,int>(_InIt,_InIt,_Ty)' being compiled
        with
        [
            _Ty=int,
            _InIt=N::C *
        ]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(20): error C2893: Failed to specialize function template 'unknown-type std::plus<void>::operator ()(_Ty1 &&,_Ty2 &&) const'
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(20): note: With the following template arguments:
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(20): note: '_Ty1=int &'
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\numeric(20): note: '_Ty2=N::C &'
Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x64