diff --git a/vec.cc b/vec.cc
index 6425bbd..7fe3348 100644
--- a/vec.cc
+++ b/vec.cc
@@ -163,6 +163,8 @@ const NRVec<double> NRVec<double>::operator-() const {
 	return result;
 }
 
+
+
 /***************************************************************************//**
  * unary minus operator in case of complex double-precision vector
  * @return the modified vector by value
@@ -981,6 +983,46 @@ INSTANTIZE_NONCOMPLEX(unsigned long long)
 INSTANTIZE_NONCOMPLEX(float)
 INSTANTIZE_NONCOMPLEX(double)
 
+
+
+
+/***************************************************************************
+ *some efficient specializations of concatenations for plain data types
+ ******************************************************************************/
+
+#define INSTANTIZE_CONCAT(T) \
+template<> \
+NRVec<T> NRVec<T>::concat(const NRVec<T> &rhs) const \
+{ \
+if(nn==0) return rhs; \
+if(rhs.nn==0) return *this; \
+NOT_GPU(*this); \
+NOT_GPU(rhs); \
+NRVec<T> r(nn+rhs.nn); \
+memcpy(r.v,v,nn*sizeof(T)); \
+memcpy(r.v+nn,rhs.v,rhs.nn*sizeof(T)); \
+return r; \
+} \
+
+
+INSTANTIZE_CONCAT(char)
+INSTANTIZE_CONCAT(unsigned char)
+INSTANTIZE_CONCAT(short)
+INSTANTIZE_CONCAT(unsigned short)
+INSTANTIZE_CONCAT(int)
+INSTANTIZE_CONCAT(unsigned int)
+INSTANTIZE_CONCAT(long)
+INSTANTIZE_CONCAT(unsigned long)
+INSTANTIZE_CONCAT(long long)
+INSTANTIZE_CONCAT(unsigned long long)
+INSTANTIZE_CONCAT(float)
+INSTANTIZE_CONCAT(double)
+INSTANTIZE_CONCAT(std::complex<float>)
+INSTANTIZE_CONCAT(std::complex<double>)
+
+
+
+
 template class NRVec<double>;
 template class NRVec<std::complex<double> >;
 template class NRVec<char>;
diff --git a/vec.h b/vec.h
index 456aa0a..2be55a0 100644
--- a/vec.h
+++ b/vec.h
@@ -222,7 +222,17 @@ public:
 	inline const NRVec operator-(const T &a) const;
 	inline const NRVec operator*(const T &a) const;
 	inline const NRVec operator/(const T &a) const;
-
+	
+	//!concatenate vectors
+	NRVec concat(const NRVec &rhs) const 
+		{
+		if(nn==0) return rhs;
+		if(rhs.nn==0) return *this;
+		NRVec r(nn+rhs.nn);
+		for(int i=0; i<nn; ++i) r[i] = (*this)[i];
+		for(int i=0; i<rhs.nn; ++i) r[nn+i] = rhs[i];
+		return r;
+		}
 
 	//! determine the actual value of the reference counter 
 	inline int getcount() const {return count?*count:0;}