#ifndef GRID_MATH_TRACE_H
#define GRID_MATH_TRACE_H
namespace Grid {

//////////////////////////////////////////////////////////////////
// Traces: both all indices and a specific index. Indices must be
// either scalar or matrix
/////////////////////////////////////////////////////////////////

inline ComplexF trace( const ComplexF &arg){    return arg;}
inline ComplexD trace( const ComplexD &arg){    return arg;}
inline RealF trace( const RealF &arg){    return arg;}
inline RealD trace( const RealD &arg){    return arg;}

template<class vtype,int N>
inline auto trace(const iMatrix<vtype,N> &arg) -> iScalar<decltype(trace(arg._internal[0][0]))>
{
    iScalar<decltype( trace(arg._internal[0][0] )) > ret;
    zeroit(ret._internal);
    for(int i=0;i<N;i++){
        ret._internal=ret._internal+trace(arg._internal[i][i]);
    }
    return ret;
}

template<class vtype>
inline auto trace(const iScalar<vtype> &arg) -> iScalar<decltype(trace(arg._internal))>
{
    iScalar<decltype(trace(arg._internal))> ret;
    ret._internal=trace(arg._internal);
    return ret;
}

template<class vtype,int N>
  inline auto trace(const iVector<vtype,N> &arg) -> iVector<decltype(trace(arg._internal[0])),N>
{
  iVector<decltype(trace(arg._internal[0])),N> ret;
  for(int i=0;i<N;i++){
    ret._internal[i]=trace(arg._internal[i]);
  }
  return ret;
}


}
#endif