diff --git a/src/common/aka_array.hh b/src/common/aka_array.hh
index 557051299..a1c08394c 100644
--- a/src/common/aka_array.hh
+++ b/src/common/aka_array.hh
@@ -1,392 +1,397 @@
 /**
  * @file   aka_array.hh
  *
  * @author Till Junge <till.junge@epfl.ch>
  * @author Nicolas Richart <nicolas.richart@epfl.ch>
  *
  * @date creation: Fri Jun 18 2010
  * @date last modification: Fri Jan 22 2016
  *
  * @brief  Array container for Akantu
  * This container differs from the std::vector from the fact it as 2 dimensions
  * a main dimension and the size stored per entries
  *
  * @section LICENSE
  *
  * Copyright (©)  2010-2012, 2014,  2015 EPFL  (Ecole Polytechnique  Fédérale de
  * Lausanne)  Laboratory (LSMS  -  Laboratoire de  Simulation  en Mécanique  des
  * Solides)
  *
  * Akantu is free  software: you can redistribute it and/or  modify it under the
  * terms  of the  GNU Lesser  General Public  License as  published by  the Free
  * Software Foundation, either version 3 of the License, or (at your option) any
  * later version.
  *
  * Akantu is  distributed in the  hope that it  will be useful, but  WITHOUT ANY
  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  * A  PARTICULAR PURPOSE. See  the GNU  Lesser General  Public License  for more
  * details.
  *
  * You should  have received  a copy  of the GNU  Lesser General  Public License
  * along with Akantu. If not, see <http://www.gnu.org/licenses/>.
  *
  */
 
 /* -------------------------------------------------------------------------- */
 
 #ifndef __AKANTU_VECTOR_HH__
 #define __AKANTU_VECTOR_HH__
 
 /* -------------------------------------------------------------------------- */
 #include "aka_common.hh"
 /* -------------------------------------------------------------------------- */
 #include <typeinfo>
 #include <vector>
 /* -------------------------------------------------------------------------- */
 
 namespace akantu {
 
 /// class that afford to store vectors in static memory
 class ArrayBase {
   /* ------------------------------------------------------------------------ */
   /* Constructors/Destructors                                                 */
   /* ------------------------------------------------------------------------ */
 public:
-  ArrayBase(ID id = "");
+  explicit ArrayBase(ID id = "");
 
   virtual ~ArrayBase();
 
   /* ------------------------------------------------------------------------ */
   /* Methods                                                                  */
   /* ------------------------------------------------------------------------ */
 public:
   /// get the amount of space allocated in bytes
   inline UInt getMemorySize() const;
 
   /// set the size to zero without freeing the allocated space
   inline void empty();
 
   /// function to print the containt of the class
   virtual void printself(std::ostream & stream, int indent = 0) const;
 
   /* ------------------------------------------------------------------------ */
   /* Accessors */
   /* ------------------------------------------------------------------------ */
 public:
   /// Get the real size allocated in memory
   AKANTU_GET_MACRO(AllocatedSize, allocated_size, UInt);
   /// Get the Size of the Array
   AKANTU_GET_MACRO(Size, size, UInt);
   /// Get the number of components
   AKANTU_GET_MACRO(NbComponent, nb_component, UInt);
   /// Get the name of th array
   AKANTU_GET_MACRO(ID, id, const ID &);
   /// Set the name of th array
   AKANTU_SET_MACRO(ID, id, const ID &);
 
   // AKANTU_GET_MACRO(Tag, tag, const std::string &);
   // AKANTU_SET_MACRO(Tag, tag, const std::string &);
 
   /* ------------------------------------------------------------------------ */
   /* Class Members                                                            */
   /* ------------------------------------------------------------------------ */
 protected:
   /// id of the vector
   ID id;
 
   /// the size allocated
   UInt allocated_size{0};
 
   /// the size used
   UInt size{0};
 
   /// number of components
   UInt nb_component{1};
 
   /// size of the stored type
   UInt size_of_type{0};
 };
 
 /* -------------------------------------------------------------------------- */
 
 /* -------------------------------------------------------------------------- */
 template <typename T, bool is_scal> class Array : public ArrayBase {
   /* ------------------------------------------------------------------------ */
   /* Constructors/Destructors                                                 */
   /* ------------------------------------------------------------------------ */
 public:
   using value_type = T;
   using reference = value_type &;
   using pointer_type = value_type *;
   using const_reference = const value_type &;
 
   /// Allocation of a new vector
-  inline Array(UInt size = 0, UInt nb_component = 1, const ID & id = "");
+  explicit inline Array(UInt size = 0, UInt nb_component = 1, const ID & id = "");
 
   /// Allocation of a new vector with a default value
   Array(UInt size, UInt nb_component, const value_type def_values[],
         const ID & id = "");
 
   /// Allocation of a new vector with a default value
   Array(UInt size, UInt nb_component, const_reference value,
         const ID & id = "");
 
   /// Copy constructor (deep copy if deep=true)
   Array(const Array<value_type, is_scal> & vect, bool deep = true,
         const ID & id = "");
 
 #ifndef SWIG
   /// Copy constructor (deep copy)
-  Array(const std::vector<value_type> & vect);
+  explicit Array(const std::vector<value_type> & vect);
 #endif
 
   inline ~Array() override;
 
   Array & operator=(const Array & a) {
     /// this is to let STL allocate and copy arrays in the case of
     /// std::vector::resize
     AKANTU_DEBUG_ASSERT(this->size == 0, "Cannot copy akantu::Array");
     return const_cast<Array &>(a);
   }
 
   /* ------------------------------------------------------------------------ */
   /* Iterator                                                                 */
   /* ------------------------------------------------------------------------ */
   /// \todo protected: does not compile with intel  check why
 public:
   template <class R, class IR = R, bool issame = is_same<IR, T>::value>
   class iterator_internal;
 
 public:
   /* ------------------------------------------------------------------------ */
 
   /* ------------------------------------------------------------------------ */
   template <typename R = T> class const_iterator;
   template <typename R = T> class iterator;
 
   /* ------------------------------------------------------------------------ */
 
   /// iterator for Array of nb_component = 1
   using scalar_iterator = iterator<T>;
   /// const_iterator for Array of nb_component = 1
   using const_scalar_iterator = const_iterator<T>;
 
   /// iterator rerturning Vectors of size n  on entries of Array with
   /// nb_component = n
   using vector_iterator = iterator<Vector<T>>;
   /// const_iterator rerturning Vectors of n size on entries of Array with
   /// nb_component = n
   using const_vector_iterator = const_iterator<Vector<T>>;
 
   /// iterator rerturning Matrices of size (m, n) on entries of Array with
   /// nb_component = m*n
   using matrix_iterator = iterator<Matrix<T>>;
   /// const iterator rerturning Matrices of size (m, n) on entries of Array with
   /// nb_component = m*n
   using const_matrix_iterator = const_iterator<Matrix<T>>;
 
   /* ------------------------------------------------------------------------ */
   /// Get an iterator that behaves like a pointer T * to the first entry
   inline scalar_iterator begin();
   /// Get an iterator that behaves like a pointer T * to the end of the Array
   inline scalar_iterator end();
   /// Get a const_iterator to the beginging of an Array of scalar
   inline const_scalar_iterator begin() const;
   /// Get a const_iterator to the end of an Array of scalar
   inline const_scalar_iterator end() const;
 
   /// Get a scalar_iterator on the beginning of the Array considered of shape
   /// (new_size)
   inline scalar_iterator begin_reinterpret(UInt new_size);
   /// Get a scalar_iterator on the end of the Array considered of shape
   /// (new_size)
   inline scalar_iterator end_reinterpret(UInt new_size);
   /// Get a const_scalar_iterator on the beginning of the Array considered of
   /// shape (new_size)
   inline const_scalar_iterator begin_reinterpret(UInt new_size) const;
   /// Get a const_scalar_iterator on the end of the Array considered of shape
   /// (new_size)
   inline const_scalar_iterator end_reinterpret(UInt new_size) const;
 
   /* ------------------------------------------------------------------------ */
   /// Get a vector_iterator on the beginning of the Array
   inline vector_iterator begin(UInt n);
   /// Get a vector_iterator on the end of the Array
   inline vector_iterator end(UInt n);
   /// Get a vector_iterator on the beginning of the Array
   inline const_vector_iterator begin(UInt n) const;
   /// Get a vector_iterator on the end of the Array
   inline const_vector_iterator end(UInt n) const;
 
   /// Get a vector_iterator on the begining of the Array considered of shape
   /// (new_size, n)
   inline vector_iterator begin_reinterpret(UInt n, UInt new_size);
   /// Get a vector_iterator on the end of the Array considered of shape
   /// (new_size, n)
   inline vector_iterator end_reinterpret(UInt n, UInt new_size);
   /// Get a const_vector_iterator on the begining of the Array considered of
   /// shape (new_size, n)
   inline const_vector_iterator begin_reinterpret(UInt n, UInt new_size) const;
   /// Get a const_vector_iterator on the end of the Array considered of shape
   /// (new_size, n)
   inline const_vector_iterator end_reinterpret(UInt n, UInt new_size) const;
 
   /* ------------------------------------------------------------------------ */
   /// Get a matrix_iterator on the begining of the Array (Matrices of size (m,
   /// n))
   inline matrix_iterator begin(UInt m, UInt n);
   /// Get a matrix_iterator on the end of the Array (Matrices of size (m, n))
   inline matrix_iterator end(UInt m, UInt n);
   /// Get a const_matrix_iterator on the begining of the Array (Matrices of size
   /// (m, n))
   inline const_matrix_iterator begin(UInt m, UInt n) const;
   /// Get a const_matrix_iterator on the end of the Array (Matrices of size (m,
   /// n))
   inline const_matrix_iterator end(UInt m, UInt n) const;
 
   /// Get a matrix_iterator on the begining of the Array considered of shape
   /// (new_size, m*n)
   inline matrix_iterator begin_reinterpret(UInt m, UInt n, UInt size);
   /// Get a matrix_iterator on the end of the Array considered of shape
   /// (new_size, m*n)
   inline matrix_iterator end_reinterpret(UInt m, UInt n, UInt size);
   /// Get a const_matrix_iterator on the begining of the Array considered of
   /// shape (new_size, m*n)
   inline const_matrix_iterator begin_reinterpret(UInt m, UInt n,
                                                  UInt size) const;
   /// Get a const_matrix_iterator on the end of the Array considered of shape
   /// (new_size, m*n)
   inline const_matrix_iterator end_reinterpret(UInt m, UInt n, UInt size) const;
 
   /* ------------------------------------------------------------------------ */
   /* Methods                                                                  */
   /* ------------------------------------------------------------------------ */
 public:
   /// append a tuple of size nb_component containing value
   inline void push_back(const_reference value);
   /// append a vector
   // inline void push_back(const value_type new_elem[]);
 
   /// append a Vector or a Matrix
   template <template <typename> class C>
   inline void push_back(const C<T> & new_elem);
   /// append the value of the iterator
   template <typename Ret> inline void push_back(const iterator<Ret> & it);
 
   /// erase the value at position i
   inline void erase(UInt i);
   /// ask Nico, clarify
   template <typename R> inline iterator<R> erase(const iterator<R> & it);
 
+  /// changes the allocated size but not the size
+  virtual void reserve(UInt size);
+
   /// change the size of the Array
   virtual void resize(UInt size);
 
   /// change the size of the Array and initialize the values
   virtual void resize(UInt size, const T & val);
 
   /// change the number of components by interlacing data
   /// @param multiplicator number of interlaced components add
   /// @param block_size blocks of data in the array
   /// Examaple for block_size = 2, multiplicator = 2
   /// array = oo oo oo -> new array = oo nn nn oo nn nn oo nn nn
   void extendComponentsInterlaced(UInt multiplicator, UInt stride);
 
   /// search elem in the vector, return  the position of the first occurrence or
   /// -1 if not found
-  Int find(const_reference elem)
-      const; /// @see Array::find(const_reference elem) const
+  Int find(const_reference elem) const;
+
+  /// @see Array::find(const_reference elem) const
   Int find(T elem[]) const;
+
   /// @see Array::find(const_reference elem) const
   template <template <typename> class C> inline Int find(const C<T> & elem);
 
   /// set all entries of the array to 0
   inline void clear() { std::fill_n(values, size * nb_component, T()); }
 
   /// set all entries of the array to the value t
   /// @param t value to fill the array with
   inline void set(T t) { std::fill_n(values, size * nb_component, t); }
 
   /// set all tuples of the array to a given vector or matrix
   /// @param vm Matrix or Vector to fill the array with
   template <template <typename> class C> inline void set(const C<T> & vm);
 
   /// Append the content of the other array to the current one
   void append(const Array<T> & other);
 
   /// copy another Array in the current Array, the no_sanity_check allows you to
   /// force the copy in cases where you know what you do with two non matching
   /// Arrays in terms of n
   void copy(const Array<T, is_scal> & other, bool no_sanity_check = false);
 
   /// give the address of the memory allocated for this vector
   T * storage() const { return values; };
 
   /// function to print the containt of the class
   void printself(std::ostream & stream, int indent = 0) const override;
 
 protected:
   /// perform the allocation for the constructors
   void allocate(UInt size, UInt nb_component = 1);
 
   /// resize initializing with uninitialized_fill if fill is set
   void resizeUnitialized(UInt new_size, bool fill, const T & val = T());
 
   /* ------------------------------------------------------------------------ */
   /* Operators                                                                */
   /* ------------------------------------------------------------------------ */
 public:
   /// substraction entry-wise
   Array<T, is_scal> & operator-=(const Array<T, is_scal> & other);
   /// addition entry-wise
   Array<T, is_scal> & operator+=(const Array<T, is_scal> & other);
   /// multiply evry entry by alpha
   Array<T, is_scal> & operator*=(const T & alpha);
 
   /// check if the array are identical entry-wise
   bool operator==(const Array<T, is_scal> & other) const;
   /// @see Array::operator==(const Array<T, is_scal> & other) const
   bool operator!=(const Array<T, is_scal> & other) const;
 
   /// return a reference to the j-th entry of the i-th tuple
   inline reference operator()(UInt i, UInt j = 0);
   /// return a const reference to the j-th entry of the i-th tuple
   inline const_reference operator()(UInt i, UInt j = 0) const;
 
   /// return a reference to the ith component of the 1D array
   inline reference operator[](UInt i);
   /// return a const reference to the ith component of the 1D array
   inline const_reference operator[](UInt i) const;
 
   /* ------------------------------------------------------------------------ */
   /* Class Members                                                            */
   /* ------------------------------------------------------------------------ */
 protected:
   /// array of values
   T * values; // /!\ very dangerous
 };
 
 /* -------------------------------------------------------------------------- */
 /* Inline Functions Array<T, is_scal>                                         */
 /* -------------------------------------------------------------------------- */
 template <typename T, bool is_scal>
 inline std::ostream & operator<<(std::ostream & stream,
                                  const Array<T, is_scal> & _this) {
   _this.printself(stream);
   return stream;
 }
 
 /* -------------------------------------------------------------------------- */
 /* Inline Functions ArrayBase                                                 */
 /* -------------------------------------------------------------------------- */
 inline std::ostream & operator<<(std::ostream & stream,
                                  const ArrayBase & _this) {
   _this.printself(stream);
   return stream;
 }
 
 } // namespace akantu
 
 #include "aka_array_tmpl.hh"
 #include "aka_types.hh"
 
 #endif /* __AKANTU_VECTOR_HH__ */
diff --git a/src/common/aka_array_tmpl.hh b/src/common/aka_array_tmpl.hh
index 364cdd368..e20a4dcf0 100644
--- a/src/common/aka_array_tmpl.hh
+++ b/src/common/aka_array_tmpl.hh
@@ -1,1542 +1,1549 @@
 /**
  * @file   aka_array_tmpl.hh
  *
  * @author Nicolas Richart <nicolas.richart@epfl.ch>
  *
  * @date creation: Thu Jul 15 2010
  * @date last modification: Fri Jan 22 2016
  *
  * @brief  Inline functions of the classes Array<T> and ArrayBase
  *
  * @section LICENSE
  *
  * Copyright (©)  2010-2012, 2014,  2015 EPFL  (Ecole Polytechnique  Fédérale de
  * Lausanne)  Laboratory (LSMS  -  Laboratoire de  Simulation  en Mécanique  des
  * Solides)
  *
  * Akantu is free  software: you can redistribute it and/or  modify it under the
  * terms  of the  GNU Lesser  General Public  License as  published by  the Free
  * Software Foundation, either version 3 of the License, or (at your option) any
  * later version.
  *
  * Akantu is  distributed in the  hope that it  will be useful, but  WITHOUT ANY
  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  * A  PARTICULAR PURPOSE. See  the GNU  Lesser General  Public License  for more
  * details.
  *
  * You should  have received  a copy  of the GNU  Lesser General  Public License
  * along with Akantu. If not, see <http://www.gnu.org/licenses/>.
  *
  */
 
 /* -------------------------------------------------------------------------- */
 /* Inline Functions Array<T>                                                 */
 /* -------------------------------------------------------------------------- */
 #include "aka_array.hh"
 /* -------------------------------------------------------------------------- */
 #include <memory>
 /* -------------------------------------------------------------------------- */
 
 #ifndef __AKANTU_AKA_ARRAY_TMPL_HH__
 #define __AKANTU_AKA_ARRAY_TMPL_HH__
 
 namespace akantu {
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline T & Array<T, is_scal>::operator()(UInt i, UInt j) {
   AKANTU_DEBUG_ASSERT(size > 0, "The array \"" << id << "\" is empty");
   AKANTU_DEBUG_ASSERT((i < size) && (j < nb_component),
                       "The value at position ["
                           << i << "," << j << "] is out of range in array \""
                           << id << "\"");
   return values[i * nb_component + j];
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline const T & Array<T, is_scal>::operator()(UInt i, UInt j) const {
   AKANTU_DEBUG_ASSERT(size > 0, "The array \"" << id << "\" is empty");
   AKANTU_DEBUG_ASSERT((i < size) && (j < nb_component),
                       "The value at position ["
                           << i << "," << j << "] is out of range in array \""
                           << id << "\"");
   return values[i * nb_component + j];
 }
 
 template <class T, bool is_scal>
 inline T & Array<T, is_scal>::operator[](UInt i) {
   AKANTU_DEBUG_ASSERT(size > 0, "The array \"" << id << "\" is empty");
   AKANTU_DEBUG_ASSERT((i < size * nb_component),
                       "The value at position ["
                           << i << "] is out of range in array \"" << id
                           << "\"");
   return values[i];
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline const T & Array<T, is_scal>::operator[](UInt i) const {
   AKANTU_DEBUG_ASSERT(size > 0, "The array \"" << id << "\" is empty");
   AKANTU_DEBUG_ASSERT((i < size * nb_component),
                       "The value at position ["
                           << i << "] is out of range in array \"" << id
                           << "\"");
   return values[i];
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * append a tuple to the array with the value value for all components
  * @param value the new last tuple or the array will contain nb_component copies
  * of value
  */
 template <class T, bool is_scal>
 inline void Array<T, is_scal>::push_back(const T & value) {
   resizeUnitialized(size + 1, true, value);
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * append a tuple to the array
  * @param new_elem a C-array containing the values to be copied to the end of
  * the array */
 // template <class T, bool is_scal>
 // inline void Array<T, is_scal>::push_back(const T new_elem[]) {
 //   UInt pos = size;
 
 //   resizeUnitialized(size + 1, false);
 
 //   T * tmp = values + nb_component * pos;
 //   std::uninitialized_copy(new_elem, new_elem + nb_component, tmp);
 // }
 
 /* -------------------------------------------------------------------------- */
 /**
  * append a matrix or a vector to the array
  * @param new_elem a reference to a Matrix<T> or Vector<T> */
 template <class T, bool is_scal>
 template <template <typename> class C>
 inline void Array<T, is_scal>::push_back(const C<T> & new_elem) {
   AKANTU_DEBUG_ASSERT(
       nb_component == new_elem.size(),
       "The vector("
           << new_elem.size()
           << ") as not a size compatible with the Array (nb_component="
           << nb_component << ").");
   UInt pos = size;
   resizeUnitialized(size + 1, false);
 
   T * tmp = values + nb_component * pos;
   std::uninitialized_copy(new_elem.storage(), new_elem.storage() + nb_component,
                           tmp);
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * append a tuple to the array
  * @param it an iterator to the tuple to be copied to the end of the array */
 template <class T, bool is_scal>
 template <class Ret>
 inline void
 Array<T, is_scal>::push_back(const Array<T, is_scal>::iterator<Ret> & it) {
   UInt pos = size;
 
   resizeUnitialized(size + 1, false);
 
   T * tmp = values + nb_component * pos;
   T * new_elem = it.data();
   std::uninitialized_copy(new_elem, new_elem + nb_component, tmp);
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * erase an element. If the erased element is not the last of the array, the
  * last element is moved into the hole in order to maintain contiguity. This
  * may invalidate existing iterators (For instance an iterator obtained by
  * Array::end() is no longer correct) and will change the order of the
  * elements.
  * @param i index of element to erase
  */
 template <class T, bool is_scal> inline void Array<T, is_scal>::erase(UInt i) {
   AKANTU_DEBUG_IN();
   AKANTU_DEBUG_ASSERT((size > 0), "The array is empty");
   AKANTU_DEBUG_ASSERT((i < size), "The element at position ["
                                       << i << "] is out of range (" << i
                                       << ">=" << size << ")");
 
   if (i != (size - 1)) {
     for (UInt j = 0; j < nb_component; ++j) {
       values[i * nb_component + j] = values[(size - 1) * nb_component + j];
     }
   }
 
   resize(size - 1);
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Subtract another array entry by entry from this array in place. Both arrays
  * must
  * have the same size and nb_component. If the arrays have different shapes,
  * code compiled in debug mode will throw an expeption and optimised code
  * will behave in an unpredicted manner
  * @param other array to subtract from this
  * @return reference to modified this
  */
 template <class T, bool is_scal>
 Array<T, is_scal> & Array<T, is_scal>::
 operator-=(const Array<T, is_scal> & vect) {
   AKANTU_DEBUG_ASSERT((size == vect.size) &&
                           (nb_component == vect.nb_component),
                       "The too array don't have the same sizes");
 
   T * a = values;
   T * b = vect.storage();
   for (UInt i = 0; i < size * nb_component; ++i) {
     *a -= *b;
     ++a;
     ++b;
   }
 
   return *this;
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Add another array entry by entry to this array in place. Both arrays must
  * have the same size and nb_component. If the arrays have different shapes,
  * code compiled in debug mode will throw an expeption and optimised code
  * will behave in an unpredicted manner
  * @param other array to add to this
  * @return reference to modified this
  */
 template <class T, bool is_scal>
 Array<T, is_scal> & Array<T, is_scal>::
 operator+=(const Array<T, is_scal> & vect) {
   AKANTU_DEBUG_ASSERT((size == vect.size) &&
                           (nb_component == vect.nb_component),
                       "The too array don't have the same sizes");
 
   T * a = values;
   T * b = vect.storage();
   for (UInt i = 0; i < size * nb_component; ++i) {
     *a++ += *b++;
   }
 
   return *this;
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Multiply all entries of this array by a scalar in place
  * @param alpha scalar multiplicant
  * @return reference to modified this
  */
 template <class T, bool is_scal>
 Array<T, is_scal> & Array<T, is_scal>::operator*=(const T & alpha) {
   T * a = values;
   for (UInt i = 0; i < size * nb_component; ++i) {
     *a++ *= alpha;
   }
 
   return *this;
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Compare this array element by element to another.
  * @param other array to compare to
  * @return true it all element are equal and arrays have the same shape, else
  * false
  */
 template <class T, bool is_scal>
 bool Array<T, is_scal>::operator==(const Array<T, is_scal> & array) const {
   bool equal = nb_component == array.nb_component && size == array.size &&
                id == array.id;
   if (!equal)
     return false;
 
   if (values == array.storage())
     return true;
   else
     return std::equal(values, values + size * nb_component, array.storage());
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 bool Array<T, is_scal>::operator!=(const Array<T, is_scal> & array) const {
   return !operator==(array);
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * set all tuples of the array to a given vector or matrix
  * @param vm Matrix or Vector to fill the array with
  */
 template <class T, bool is_scal>
 template <template <typename> class C>
 inline void Array<T, is_scal>::set(const C<T> & vm) {
   AKANTU_DEBUG_ASSERT(
       nb_component == vm.size(),
       "The size of the object does not match the number of components");
   for (T * it = values; it < values + nb_component * size; it += nb_component) {
     std::copy(vm.storage(), vm.storage() + nb_component, it);
   }
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 void Array<T, is_scal>::append(const Array<T> & other) {
   AKANTU_DEBUG_ASSERT(
       nb_component == other.nb_component,
       "Cannot append an array with a different number of component");
   UInt old_size = this->size;
   this->resizeUnitialized(this->size + other.getSize(), false);
 
   T * tmp = values + nb_component * old_size;
   std::uninitialized_copy(
       other.storage(), other.storage() + other.getSize() * nb_component, tmp);
 }
 
 /* -------------------------------------------------------------------------- */
 /* Functions Array<T, is_scal>                                                */
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 Array<T, is_scal>::Array(UInt size, UInt nb_component, const ID & id)
     : ArrayBase(id), values(NULL) {
   AKANTU_DEBUG_IN();
   allocate(size, nb_component);
 
   if (!is_scal) {
     T val = T();
     std::uninitialized_fill(values, values + size * nb_component, val);
   }
 
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 Array<T, is_scal>::Array(UInt size, UInt nb_component, const T def_values[],
                          const ID & id)
     : ArrayBase(id), values(NULL) {
   AKANTU_DEBUG_IN();
   allocate(size, nb_component);
 
   T * tmp = values;
 
   for (UInt i = 0; i < size; ++i) {
     tmp = values + nb_component * i;
     std::uninitialized_copy(def_values, def_values + nb_component, tmp);
   }
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 Array<T, is_scal>::Array(UInt size, UInt nb_component, const T & value,
                          const ID & id)
     : ArrayBase(id), values(NULL) {
   AKANTU_DEBUG_IN();
   allocate(size, nb_component);
 
   std::uninitialized_fill_n(values, size * nb_component, value);
 
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 Array<T, is_scal>::Array(const Array<T, is_scal> & vect, bool deep,
                          const ID & id)
     : ArrayBase(vect) {
   AKANTU_DEBUG_IN();
   this->id = (id == "") ? vect.id : id;
 
   if (deep) {
     allocate(vect.size, vect.nb_component);
     T * tmp = values;
     std::uninitialized_copy(vect.storage(),
                             vect.storage() + size * nb_component, tmp);
   } else {
     this->values = vect.storage();
     this->size = vect.size;
     this->nb_component = vect.nb_component;
     this->allocated_size = vect.allocated_size;
     this->size_of_type = vect.size_of_type;
   }
 
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 #ifndef SWIG
 template <class T, bool is_scal>
 Array<T, is_scal>::Array(const std::vector<T> & vect) {
   AKANTU_DEBUG_IN();
   this->id = "";
 
   allocate(vect.size(), 1);
   T * tmp = values;
   std::uninitialized_copy(&(vect[0]), &(vect[size - 1]), tmp);
 
   AKANTU_DEBUG_OUT();
 }
 #endif
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal> Array<T, is_scal>::~Array() {
   AKANTU_DEBUG_IN();
   AKANTU_DEBUG(dblAccessory,
                "Freeing " << printMemorySize<T>(allocated_size * nb_component)
                           << " (" << id << ")");
 
   if (values) {
     if (!is_scal)
       for (UInt i = 0; i < size * nb_component; ++i) {
         T * obj = values + i;
         obj->~T();
       }
     free(values);
   }
   size = allocated_size = 0;
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * perform the allocation for the constructors
  * @param size is the size of the array
  * @param nb_component is the number of component of the array
  */
 template <class T, bool is_scal>
 void Array<T, is_scal>::allocate(UInt size, UInt nb_component) {
   AKANTU_DEBUG_IN();
   if (size == 0) {
     values = NULL;
   } else {
     values = static_cast<T *>(malloc(nb_component * size * sizeof(T)));
     AKANTU_DEBUG_ASSERT(values != NULL,
                         "Cannot allocate "
                             << printMemorySize<T>(size * nb_component) << " ("
                             << id << ")");
   }
 
   if (values == NULL) {
     this->size = this->allocated_size = 0;
   } else {
     AKANTU_DEBUG(dblAccessory, "Allocated "
                                    << printMemorySize<T>(size * nb_component)
                                    << " (" << id << ")");
     this->size = this->allocated_size = size;
   }
 
   this->size_of_type = sizeof(T);
   this->nb_component = nb_component;
 
   AKANTU_DEBUG_OUT();
 }
 
+/* -------------------------------------------------------------------------- */
+template <class T, bool is_scal> void Array<T, is_scal>::reserve(UInt new_size) {
+  UInt tmp_size = this->size;
+  resizeUnitialized(new_size, false);
+  this->size = tmp_size;
+}
+
 /* -------------------------------------------------------------------------- */
 /**
  * change the size of the array and allocate or free memory if needed. If the
  * size increases, the new tuples are filled with zeros
  * @param new_size new number of tuples contained in the array */
 template <class T, bool is_scal> void Array<T, is_scal>::resize(UInt new_size) {
   resizeUnitialized(new_size, !is_scal);
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * change the size of the array and allocate or free memory if needed. If the
  * size increases, the new tuples are filled with zeros
  * @param new_size new number of tuples contained in the array */
 template <class T, bool is_scal>
 void Array<T, is_scal>::resize(UInt new_size, const T & val) {
   this->resizeUnitialized(new_size, true, val);
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * change the size of the array and allocate or free memory if needed.
  * @param new_size new number of tuples contained in the array */
 template <class T, bool is_scal>
 void Array<T, is_scal>::resizeUnitialized(UInt new_size, bool fill,
                                           const T & val) {
   //  AKANTU_DEBUG_IN();
   // free some memory
   if (new_size <= allocated_size) {
     if (!is_scal) {
       T * old_values = values;
       if (new_size < size) {
         for (UInt i = new_size * nb_component; i < size * nb_component; ++i) {
           T * obj = old_values + i;
           obj->~T();
         }
       }
     }
 
     if (allocated_size - new_size > AKANTU_MIN_ALLOCATION) {
       AKANTU_DEBUG(dblAccessory,
                    "Freeing " << printMemorySize<T>((allocated_size - size) *
                                                     nb_component)
                               << " (" << id << ")");
 
       // Normally there are no allocation problem when reducing an array
       if (new_size == 0) {
         free(values);
         values = NULL;
       } else {
         auto * tmp_ptr = static_cast<T *>(
             realloc(values, new_size * nb_component * sizeof(T)));
 
         if (tmp_ptr == NULL) {
           AKANTU_EXCEPTION("Cannot free data ("
                            << id << ")"
                            << " [current allocated size : " << allocated_size
                            << " | "
                            << "requested size : " << new_size << "]");
         }
         values = tmp_ptr;
       }
       allocated_size = new_size;
     }
   } else {
     // allocate more memory
     UInt size_to_alloc = (new_size - allocated_size < AKANTU_MIN_ALLOCATION)
                              ? allocated_size + AKANTU_MIN_ALLOCATION
                              : new_size;
 
     auto * tmp_ptr = static_cast<T *>(
         realloc(values, size_to_alloc * nb_component * sizeof(T)));
     AKANTU_DEBUG_ASSERT(
         tmp_ptr != NULL,
         "Cannot allocate " << printMemorySize<T>(size_to_alloc * nb_component));
     if (tmp_ptr == NULL) {
       AKANTU_DEBUG_ERROR("Cannot allocate more data ("
                          << id << ")"
                          << " [current allocated size : " << allocated_size
                          << " | "
                          << "requested size : " << new_size << "]");
     }
 
     AKANTU_DEBUG(dblAccessory,
                  "Allocating " << printMemorySize<T>(
                      (size_to_alloc - allocated_size) * nb_component));
 
     allocated_size = size_to_alloc;
     values = tmp_ptr;
   }
 
   if (fill && this->size < new_size) {
     std::uninitialized_fill(values + size * nb_component,
                             values + new_size * nb_component, val);
   }
 
   size = new_size;
   //  AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * change the number of components by interlacing data
  * @param multiplicator number of interlaced components add
  * @param block_size blocks of data in the array
  * Examaple for block_size = 2, multiplicator = 2
  * array = oo oo oo -> new array = oo nn nn oo nn nn oo nn nn */
 template <class T, bool is_scal>
 void Array<T, is_scal>::extendComponentsInterlaced(UInt multiplicator,
                                                    UInt block_size) {
   AKANTU_DEBUG_IN();
 
   if (multiplicator == 1)
     return;
 
   AKANTU_DEBUG_ASSERT(multiplicator > 1, "invalid multiplicator");
   AKANTU_DEBUG_ASSERT(nb_component % block_size == 0,
                       "stride must divide actual number of components");
 
   values = static_cast<T *>(
       realloc(values, nb_component * multiplicator * size * sizeof(T)));
 
   UInt new_component = nb_component / block_size * multiplicator;
 
   for (UInt i = 0, k = size - 1; i < size; ++i, --k) {
     for (UInt j = 0; j < new_component; ++j) {
       UInt m = new_component - j - 1;
       UInt n = m / multiplicator;
       for (UInt l = 0, p = block_size - 1; l < block_size; ++l, --p) {
         values[k * nb_component * multiplicator + m * block_size + p] =
             values[k * nb_component + n * block_size + p];
       }
     }
   }
 
   nb_component = nb_component * multiplicator;
 
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * search elem in the array, return  the position of the first occurrence or
  * -1 if not found
  *  @param elem the element to look for
  *  @return index of the first occurrence of elem or -1 if elem is not present
  */
 template <class T, bool is_scal>
 Int Array<T, is_scal>::find(const T & elem) const {
   AKANTU_DEBUG_IN();
   UInt i = 0;
   for (; (i < size) && (values[i] != elem); ++i)
     ;
 
   AKANTU_DEBUG_OUT();
   return (i == size) ? -1 : (Int)i;
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal> Int Array<T, is_scal>::find(T elem[]) const {
   AKANTU_DEBUG_IN();
   T * it = values;
   UInt i = 0;
   for (; i < size; ++i) {
     if (*it == elem[0]) {
       T * cit = it;
       UInt c = 0;
       for (; (c < nb_component) && (*cit == elem[c]); ++c, ++cit)
         ;
       if (c == nb_component) {
         AKANTU_DEBUG_OUT();
         return i;
       }
     }
     it += nb_component;
   }
   return -1;
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 template <template <typename> class C>
 inline Int Array<T, is_scal>::find(const C<T> & elem) {
   return this->find(elem.storage());
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * copy the content of another array. This overwrites the current content.
  * @param other Array to copy into this array. It has to have the same
  * nb_component as this. If compiled in debug mode, an incorrect other will
  * result in an exception being thrown. Optimised code may result in
  * unpredicted behaviour.
  */
 template <class T, bool is_scal>
 void Array<T, is_scal>::copy(const Array<T, is_scal> & vect,
                              bool no_sanity_check) {
   AKANTU_DEBUG_IN();
 
   if (!no_sanity_check)
     if (vect.nb_component != nb_component)
       AKANTU_DEBUG_ERROR(
           "The two arrays do not have the same number of components");
 
   resize((vect.size * vect.nb_component) / nb_component);
 
   T * tmp = values;
   std::uninitialized_copy(vect.storage(), vect.storage() + size * nb_component,
                           tmp);
 
   AKANTU_DEBUG_OUT();
 }
 
 /* -------------------------------------------------------------------------- */
 template <bool is_scal> class ArrayPrintHelper {
 public:
   template <typename T>
   static void print_content(const Array<T> & vect, std::ostream & stream,
                             int indent) {
     if (AKANTU_DEBUG_TEST(dblDump) || AKANTU_DEBUG_LEVEL_IS_TEST()) {
       std::string space;
       for (Int i = 0; i < indent; i++, space += AKANTU_INDENT)
         ;
 
       stream << space << " + values         : {";
       for (UInt i = 0; i < vect.getSize(); ++i) {
         stream << "{";
         for (UInt j = 0; j < vect.getNbComponent(); ++j) {
           stream << vect(i, j);
           if (j != vect.getNbComponent() - 1)
             stream << ", ";
         }
         stream << "}";
         if (i != vect.getSize() - 1)
           stream << ", ";
       }
       stream << "}" << std::endl;
     }
   }
 };
 
 template <> class ArrayPrintHelper<false> {
 public:
   template <typename T>
   static void print_content(__attribute__((unused)) const Array<T> & vect,
                             __attribute__((unused)) std::ostream & stream,
                             __attribute__((unused)) int indent) {}
 };
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 void Array<T, is_scal>::printself(std::ostream & stream, int indent) const {
   std::string space;
   for (Int i = 0; i < indent; i++, space += AKANTU_INDENT)
     ;
 
   std::streamsize prec = stream.precision();
   std::ios_base::fmtflags ff = stream.flags();
 
   stream.setf(std::ios_base::showbase);
   stream.precision(2);
 
   stream << space << "Array<" << debug::demangle(typeid(T).name()) << "> ["
          << std::endl;
   stream << space << " + id             : " << this->id << std::endl;
   stream << space << " + size           : " << this->size << std::endl;
   stream << space << " + nb_component   : " << this->nb_component << std::endl;
   stream << space << " + allocated size : " << this->allocated_size
          << std::endl;
   stream << space << " + memory size    : "
          << printMemorySize<T>(allocated_size * nb_component) << std::endl;
   if (!AKANTU_DEBUG_LEVEL_IS_TEST())
     stream << space << " + address        : " << std::hex << this->values
            << std::dec << std::endl;
 
   stream.precision(prec);
   stream.flags(ff);
 
   ArrayPrintHelper<is_scal>::print_content(*this, stream, indent);
 
   stream << space << "]" << std::endl;
 }
 
 /* -------------------------------------------------------------------------- */
 /* Inline Functions ArrayBase                                                */
 /* -------------------------------------------------------------------------- */
 
 inline UInt ArrayBase::getMemorySize() const {
   return allocated_size * nb_component * size_of_type;
 }
 
 inline void ArrayBase::empty() { size = 0; }
 
 /* -------------------------------------------------------------------------- */
 /* Iterators                                                                  */
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 template <class R, class IR, bool is_r_scal>
 class Array<T, is_scal>::iterator_internal {
 public:
   using value_type = R;
   using pointer = R *;
   using reference = R &;
   using proxy = typename R::proxy;
   using const_proxy = const typename R::proxy;
   using const_reference = const R &;
   using internal_value_type = IR;
   using internal_pointer = IR *;
   using difference_type = std::ptrdiff_t;
   using iterator_category = std::random_access_iterator_tag;
 
 public:
   iterator_internal() : initial(NULL), ret(NULL), ret_ptr(NULL){};
 
   iterator_internal(pointer_type data, UInt _offset)
       : _offset(_offset), initial(data), ret(NULL), ret_ptr(data) {
     AKANTU_DEBUG_ERROR(
         "The constructor should never be called it is just an ugly trick...");
   }
 
   iterator_internal(pointer wrapped)
       : _offset(wrapped->size()), initial(wrapped->storage()),
         ret(const_cast<internal_pointer>(wrapped)),
         ret_ptr(wrapped->storage()) {}
 
   iterator_internal(const iterator_internal & it) {
     if (this != &it) {
       this->_offset = it._offset;
       this->initial = it.initial;
       this->ret_ptr = it.ret_ptr;
       this->ret = new internal_value_type(*it.ret, false);
     }
   }
 
   virtual ~iterator_internal() { delete ret; };
 
   inline iterator_internal & operator=(const iterator_internal & it) {
     if (this != &it) {
       this->_offset = it._offset;
       this->initial = it.initial;
       this->ret_ptr = it.ret_ptr;
       if (this->ret)
         this->ret->shallowCopy(*it.ret);
       else
         this->ret = new internal_value_type(*it.ret, false);
     }
     return *this;
   }
 
   UInt getCurrentIndex() {
     return (this->ret_ptr - this->initial) / this->_offset;
   };
 
   inline reference operator*() {
     ret->values = ret_ptr;
     return *ret;
   };
   inline const_reference operator*() const {
     ret->values = ret_ptr;
     return *ret;
   };
   inline pointer operator->() {
     ret->values = ret_ptr;
     return ret;
   };
   inline iterator_internal & operator++() {
     ret_ptr += _offset;
     return *this;
   };
   inline iterator_internal & operator--() {
     ret_ptr -= _offset;
     return *this;
   };
 
   inline iterator_internal & operator+=(const UInt n) {
     ret_ptr += _offset * n;
     return *this;
   }
   inline iterator_internal & operator-=(const UInt n) {
     ret_ptr -= _offset * n;
     return *this;
   }
 
   inline proxy operator[](const UInt n) {
     ret->values = ret_ptr + n * _offset;
     return proxy(*ret);
   }
   inline const_proxy operator[](const UInt n) const {
     ret->values = ret_ptr + n * _offset;
     return const_proxy(*ret);
   }
 
   inline bool operator==(const iterator_internal & other) const {
     return this->ret_ptr == other.ret_ptr;
   }
   inline bool operator!=(const iterator_internal & other) const {
     return this->ret_ptr != other.ret_ptr;
   }
   inline bool operator<(const iterator_internal & other) const {
     return this->ret_ptr < other.ret_ptr;
   }
   inline bool operator<=(const iterator_internal & other) const {
     return this->ret_ptr <= other.ret_ptr;
   }
   inline bool operator>(const iterator_internal & other) const {
     return this->ret_ptr > other.ret_ptr;
   }
   inline bool operator>=(const iterator_internal & other) const {
     return this->ret_ptr >= other.ret_ptr;
   }
 
   inline iterator_internal operator+(difference_type n) {
     iterator_internal tmp(*this);
     tmp += n;
     return tmp;
   }
   inline iterator_internal operator-(difference_type n) {
     iterator_internal tmp(*this);
     tmp -= n;
     return tmp;
   }
 
   inline difference_type operator-(const iterator_internal & b) {
     return (this->ret_ptr - b.ret_ptr) / _offset;
   }
 
   inline pointer_type data() const { return ret_ptr; }
   inline difference_type offset() const { return _offset; }
 
 protected:
   UInt _offset{0};
   pointer_type initial;
   internal_pointer ret;
   pointer_type ret_ptr;
 };
 
 /* -------------------------------------------------------------------------- */
 /**
  * Specialization for scalar types
  */
 template <class T, bool is_scal>
 template <class R, class IR>
 class Array<T, is_scal>::iterator_internal<R, IR, true> {
 public:
   using value_type = R;
   using pointer = R *;
   using reference = R &;
   using const_reference = const R &;
   using internal_value_type = IR;
   using internal_pointer = IR *;
   using difference_type = std::ptrdiff_t;
   using iterator_category = std::random_access_iterator_tag;
 
 public:
   iterator_internal(pointer data = NULL,
                     __attribute__((unused)) UInt _offset = 1)
       : _offset(_offset), ret(data), initial(data){};
   iterator_internal(const iterator_internal & it) {
     if (this != &it) {
       this->ret = it.ret;
       this->initial = it.initial;
     }
   }
 
   virtual ~iterator_internal() = default;
 
   inline iterator_internal & operator=(const iterator_internal & it) {
     if (this != &it) {
       this->ret = it.ret;
       this->initial = it.initial;
     }
     return *this;
   }
 
   UInt getCurrentIndex() {
     return (this->ret - this->initial) / this->_offset;
   };
 
   inline reference operator*() { return *ret; };
   inline const_reference operator*() const { return *ret; };
   inline pointer operator->() { return ret; };
   inline iterator_internal & operator++() {
     ++ret;
     return *this;
   };
   inline iterator_internal & operator--() {
     --ret;
     return *this;
   };
 
   inline iterator_internal & operator+=(const UInt n) {
     ret += n;
     return *this;
   }
   inline iterator_internal & operator-=(const UInt n) {
     ret -= n;
     return *this;
   }
 
   inline reference operator[](const UInt n) { return ret[n]; }
 
   inline bool operator==(const iterator_internal & other) const {
     return ret == other.ret;
   }
   inline bool operator!=(const iterator_internal & other) const {
     return ret != other.ret;
   }
   inline bool operator<(const iterator_internal & other) const {
     return ret < other.ret;
   }
   inline bool operator<=(const iterator_internal & other) const {
     return ret <= other.ret;
   }
   inline bool operator>(const iterator_internal & other) const {
     return ret > other.ret;
   }
   inline bool operator>=(const iterator_internal & other) const {
     return ret >= other.ret;
   }
 
   inline iterator_internal operator-(difference_type n) {
     return iterator_internal(ret - n);
   }
   inline iterator_internal operator+(difference_type n) {
     return iterator_internal(ret + n);
   }
 
   inline difference_type operator-(const iterator_internal & b) {
     return ret - b.ret;
   }
 
   inline pointer data() const { return ret; }
   inline difference_type offset() const { return _offset; }
 
 protected:
   difference_type _offset;
   pointer ret;
   pointer initial;
 };
 
 /* -------------------------------------------------------------------------- */
 /* Begin/End functions implementation                                         */
 /* -------------------------------------------------------------------------- */
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Vector<T> * to the
  * first tuple of the array.
  * @param n vector size. Has to be equal to nb_component. This unfortunate
  * redundancy is necessary to distinguish it from ::begin() which it
  * overloads. If compiled in debug mode, an incorrect value of n will result
  * in an exception being thrown. Optimized code will fail in an unpredicted
  * manner.
  * @return a vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::vector_iterator
 Array<T, is_scal>::begin(UInt n) {
   AKANTU_DEBUG_ASSERT(nb_component == n,
                       "The iterator is not compatible with the type Array("
                           << n << ")");
   return vector_iterator(new Vector<T>(values, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Vector<T> * pointing
  * *past* the last tuple of the array.
  * @param n vector size. see Array::begin(UInt n) for more
  * @return a vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::vector_iterator
 Array<T, is_scal>::end(UInt n) {
   AKANTU_DEBUG_ASSERT(nb_component == n,
                       "The iterator is not compatible with the type Array("
                           << n << ")");
   return vector_iterator(new Vector<T>(values + nb_component * size, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Vector<T> * to the
  * first tuple of the array.
  * @param n vector size. see Array::begin(UInt n) for more
  * @return a vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_vector_iterator
 Array<T, is_scal>::begin(UInt n) const {
   AKANTU_DEBUG_ASSERT(nb_component == n,
                       "The iterator is not compatible with the type Array("
                           << n << ")");
   return const_vector_iterator(new Vector<T>(values, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Vector<T> * pointing
  * *past* the last tuple of the array.
  * @param n vector size. see Array::begin(UInt n) for more
  * @return a const_vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_vector_iterator
 Array<T, is_scal>::end(UInt n) const {
   AKANTU_DEBUG_ASSERT(nb_component == n,
                       "The iterator is not compatible with the type Array("
                           << n << ")");
   return const_vector_iterator(new Vector<T>(values + nb_component * size, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Vector<T> * to the
  * first tuple of the array.
  *
  * The reinterpret iterators allow to iterate over an array in any way that
  * preserves the number of entries of the array. This can for instance be use
  * full if the shape of the data in an array is not initially known.
  * @param n vector size.
  * @param size number of tuples in array. n times size must match the number
  * of entries of the array. If compiled in debug mode, an incorrect
  * combination of n and size will result
  * in an exception being thrown. Optimized code will fail in an unpredicted
  * manner.
  * @return a vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::vector_iterator
 Array<T, is_scal>::begin_reinterpret(UInt n,
                                      __attribute__((unused)) UInt size) {
   AKANTU_DEBUG_ASSERT(n * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << n
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return vector_iterator(new Vector<T>(values, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Vector<T> * pointing
  * *past* the last tuple of the array.
  * @param n vector size.
  * @param size number of tuples in array. See Array::begin_reinterpret(UInt n,
  * UInt size)
  * @return a vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::vector_iterator
 Array<T, is_scal>::end_reinterpret(UInt n, UInt size) {
   AKANTU_DEBUG_ASSERT(n * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << n
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return vector_iterator(new Vector<T>(values + n * size, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Vector<T> * to the
  * first tuple of the array.
  * @param n vector size.
  * @param size number of tuples in array. See Array::begin_reinterpret(UInt n,
  * UInt size)
  * @return a const_vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_vector_iterator
 Array<T, is_scal>::begin_reinterpret(UInt n,
                                      __attribute__((unused)) UInt size) const {
   AKANTU_DEBUG_ASSERT(n * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << n
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return const_vector_iterator(new Vector<T>(values, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Vector<T> * pointing
  * *past* the last tuple of the array.
  * @param n vector size.
  * @param size number of tuples in array. See Array::begin_reinterpret(UInt n,
  * UInt size)
  * @return a const_vector_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_vector_iterator
 Array<T, is_scal>::end_reinterpret(UInt n, UInt size) const {
   AKANTU_DEBUG_ASSERT(n * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << n
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return const_vector_iterator(new Vector<T>(values + n * size, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Matrix<T> * to the
  * first tuple of the array.
  * @param m number of rows
  * @param n number of columns. m times n has to equal nb_component.
  * If compiled in debug mode, an incorrect combination of m and n will result
  * in an exception being thrown. Optimized code will fail in an unpredicted
  * manner.
  * @return a matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::matrix_iterator
 Array<T, is_scal>::begin(UInt m, UInt n) {
   AKANTU_DEBUG_ASSERT(nb_component == n * m,
                       "The iterator is not compatible with the type Matrix("
                           << m << "," << n << ")");
   return matrix_iterator(new Matrix<T>(values, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Matrix<T> * pointing
  * *past* the last tuple of the array.
  * @param m number of rows
  * @param n number of columns. See Array::begin(UInt m, UInt n)
  * @return a matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::matrix_iterator
 Array<T, is_scal>::end(UInt m, UInt n) {
   AKANTU_DEBUG_ASSERT(nb_component == n * m,
                       "The iterator is not compatible with the type Matrix("
                           << m << "," << n << ")");
   return matrix_iterator(new Matrix<T>(values + nb_component * size, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Matrix<T> * to the
  * first tuple of the array.
  * @param m number of rows
  * @param n number of columns. See Array::begin(UInt m, UInt n)
  * @return a matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_matrix_iterator
 Array<T, is_scal>::begin(UInt m, UInt n) const {
   AKANTU_DEBUG_ASSERT(nb_component == n * m,
                       "The iterator is not compatible with the type Matrix("
                           << m << "," << n << ")");
   return const_matrix_iterator(new Matrix<T>(values, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Matrix<T> * pointing
  * *past* the last tuple of the array.
  * @param m number of rows
  * @param n number of columns. See Array::begin(UInt m, UInt n)
  * @return a const_matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_matrix_iterator
 Array<T, is_scal>::end(UInt m, UInt n) const {
   AKANTU_DEBUG_ASSERT(nb_component == n * m,
                       "The iterator is not compatible with the type Matrix("
                           << m << "," << n << ")");
   return const_matrix_iterator(
       new Matrix<T>(values + nb_component * size, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Matrix<T> * to the
  * first tuple of the array.
  *
  * The reinterpret iterators allow to iterate over an array in any way that
  * preserves the number of entries of the array. This can for instance be use
  * full if the shape of the data in an array is not initially known.
  * @param m number of rows
  * @param n number of columns
  * @param size number of tuples in array. m times n times size must match the
  *number
  * of entries of the array. If compiled in debug mode, an incorrect
  * combination of m, n and size will result
  * in an exception being thrown. Optimized code will fail in an unpredicted
  * manner.
  * @return a matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::matrix_iterator
 Array<T, is_scal>::begin_reinterpret(UInt m, UInt n,
                                      __attribute__((unused)) UInt size) {
   AKANTU_DEBUG_ASSERT(n * m * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << m << "," << n
                           << " = " << n * m
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return matrix_iterator(new Matrix<T>(values, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get an iterator that behaves like a pointer akantu::Matrix<T> * pointing
  * *past* the last tuple of the array.
  * @param m number of rows
  * @param n number of columns
  * @param size number of tuples in array. See Array::begin_reinterpret(UInt m,
  * UInt n, UInt size)
  * @return a matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::matrix_iterator
 Array<T, is_scal>::end_reinterpret(UInt m, UInt n, UInt size) {
   AKANTU_DEBUG_ASSERT(n * m * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << m << "," << n
                           << " = " << n * m
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return matrix_iterator(new Matrix<T>(values + n * m * size, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Matrix<T> * to the
  * first tuple of the array.
  * @param m number of rows
  * @param n number of columns
  * @param size number of tuples in array. See Array::begin_reinterpret(UInt m,
  * UInt n, UInt size)
  * @return a const_matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_matrix_iterator
 Array<T, is_scal>::begin_reinterpret(UInt m, UInt n,
                                      __attribute__((unused)) UInt size) const {
   AKANTU_DEBUG_ASSERT(n * m * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << m << "," << n
                           << " = " << n * m
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return const_matrix_iterator(new Matrix<T>(values, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /**
  * Get a const iterator that behaves like a pointer akantu::Matrix<T> * pointing
  * *past* the last tuple of the array.
  * @param m number of rows
  * @param n number of columns
  * @param size number of tuples in array. See Array::begin_reinterpret(UInt m,
  * UInt n, UInt size)
  * @return a const_matrix_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_matrix_iterator
 Array<T, is_scal>::end_reinterpret(UInt m, UInt n, UInt size) const {
   AKANTU_DEBUG_ASSERT(n * m * size == this->nb_component * this->size,
                       "The new values for size ("
                           << size << ") and nb_component (" << m << "," << n
                           << " = " << n * m
                           << ") are not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return const_matrix_iterator(new Matrix<T>(values + n * m * size, m, n));
 }
 
 /* -------------------------------------------------------------------------- */
 /** Get an iterator that behaves like a pointer T * to the
  *  first entry in the member array values
  *  @return a scalar_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::scalar_iterator Array<T, is_scal>::begin() {
   AKANTU_DEBUG_ASSERT(
       nb_component == 1,
       "this iterator cannot be used on a vector which has nb_component != 1");
   return scalar_iterator(values);
 }
 
 /* -------------------------------------------------------------------------- */
 /*! Get an iterator that behaves like a pointer T * that points *past* the
  *  last entry in the member array values
  *  @return a scalar_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::scalar_iterator Array<T, is_scal>::end() {
   AKANTU_DEBUG_ASSERT(
       nb_component == 1,
       "this iterator cannot be used on a array which has nb_component != 1");
   return scalar_iterator(values + size);
 }
 
 /* -------------------------------------------------------------------------- */
 /*! Get a const iterator that behaves like a pointer T * to the
  *  first entry in the member array values
  *  @return a const_scalar_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_scalar_iterator
 Array<T, is_scal>::begin() const {
   AKANTU_DEBUG_ASSERT(
       nb_component == 1,
       "this iterator cannot be used on a array which has nb_component != 1");
   return const_scalar_iterator(values);
 }
 
 /* -------------------------------------------------------------------------- */
 /*! Get a const iterator that behaves like a pointer T * that points *past* the
  *  last entry in the member array values
  *  @return a const_scalar_iterator
  */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_scalar_iterator
 Array<T, is_scal>::end() const {
   AKANTU_DEBUG_ASSERT(
       nb_component == 1,
       "this iterator cannot be used on a array which has nb_component != 1");
   return const_scalar_iterator(values + size);
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::scalar_iterator
 Array<T, is_scal>::begin_reinterpret(__attribute__((unused)) UInt new_size) {
   AKANTU_DEBUG_ASSERT(new_size == this->nb_component * this->size,
                       "The new values for size ("
                           << new_size
                           << ") is not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return scalar_iterator(values);
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::scalar_iterator
 Array<T, is_scal>::end_reinterpret(UInt new_size) {
   AKANTU_DEBUG_ASSERT(new_size == this->nb_component * this->size,
                       "The new values for size ("
                           << new_size
                           << ") is not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return scalar_iterator(values + new_size);
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_scalar_iterator
 Array<T, is_scal>::begin_reinterpret(__attribute__((unused))
                                      UInt new_size) const {
   AKANTU_DEBUG_ASSERT(new_size == this->nb_component * this->size,
                       "The new values for size ("
                           << new_size
                           << ") is not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return const_scalar_iterator(values);
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 inline typename Array<T, is_scal>::const_scalar_iterator
 Array<T, is_scal>::end_reinterpret(UInt new_size) const {
   AKANTU_DEBUG_ASSERT(new_size == this->nb_component * this->size,
                       "The new values for size ("
                           << new_size
                           << ") is not compatible with the one of this array("
                           << this->size << "," << this->nb_component << ")");
   return const_scalar_iterator(values + new_size);
 }
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 template <typename R>
 class Array<T, is_scal>::const_iterator : public iterator_internal<const R, R> {
 public:
   typedef iterator_internal<const R, R> parent;
   using value_type = typename parent::value_type;
   using pointer = typename parent::pointer;
   using reference = typename parent::reference;
   using difference_type = typename parent::difference_type;
   using iterator_category = typename parent::iterator_category;
 
 public:
   const_iterator() : parent(){};
   const_iterator(pointer_type data, UInt offset) : parent(data, offset) {}
   const_iterator(pointer warped) : parent(warped) {}
   const_iterator(const parent & it) : parent(it) {}
   //    const_iterator(const const_iterator<R> & it) : parent(it) {}
 
   inline const_iterator operator+(difference_type n) {
     return parent::operator+(n);
   }
   inline const_iterator operator-(difference_type n) {
     return parent::operator-(n);
   }
   inline difference_type operator-(const const_iterator & b) {
     return parent::operator-(b);
   }
 
   inline const_iterator & operator++() {
     parent::operator++();
     return *this;
   };
   inline const_iterator & operator--() {
     parent::operator--();
     return *this;
   };
   inline const_iterator & operator+=(const UInt n) {
     parent::operator+=(n);
     return *this;
   }
 };
 // #endif
 
 // #if defined(AKANTU_CORE_CXX11)
 //   template<class R> using iterator = iterator_internal<R>;
 // #else
 template <class T, class R, bool issame = is_same<T, R>::value>
 struct ConstConverterIteratorHelper {
   using const_iterator = typename Array<T>::template const_iterator<R>;
   using iterator = typename Array<T>::template iterator<R>;
   static inline const_iterator convert(const iterator & it) {
     return const_iterator(new R(*it, false));
   }
 };
 
 template <class T, class R> struct ConstConverterIteratorHelper<T, R, true> {
   using const_iterator = typename Array<T>::template const_iterator<R>;
   using iterator = typename Array<T>::template iterator<R>;
   static inline const_iterator convert(const iterator & it) {
     return const_iterator(it.data(), it.offset());
   }
 };
 
 template <class T, bool is_scal>
 template <typename R>
 class Array<T, is_scal>::iterator : public iterator_internal<R> {
 public:
   using parent = iterator_internal<R>;
   using value_type = typename parent::value_type;
   using pointer = typename parent::pointer;
   using reference = typename parent::reference;
   using difference_type = typename parent::difference_type;
   using iterator_category = typename parent::iterator_category;
 
 public:
   iterator() : parent(){};
   iterator(pointer_type data, UInt offset) : parent(data, offset){};
   iterator(pointer warped) : parent(warped) {}
   iterator(const parent & it) : parent(it) {}
   //    iterator(const iterator<R> & it) : parent(it) {}
 
   operator const_iterator<R>() {
     return ConstConverterIteratorHelper<T, R>::convert(*this);
   }
 
   inline iterator operator+(difference_type n) {
     return parent::operator+(n);
     ;
   }
   inline iterator operator-(difference_type n) {
     return parent::operator-(n);
     ;
   }
   inline difference_type operator-(const iterator & b) {
     return parent::operator-(b);
   }
 
   inline iterator & operator++() {
     parent::operator++();
     return *this;
   };
   inline iterator & operator--() {
     parent::operator--();
     return *this;
   };
   inline iterator & operator+=(const UInt n) {
     parent::operator+=(n);
     return *this;
   }
 };
 
 /* -------------------------------------------------------------------------- */
 template <class T, bool is_scal>
 template <typename R>
 inline typename Array<T, is_scal>::template iterator<R>
 Array<T, is_scal>::erase(const iterator<R> & it) {
   T * curr = it.data();
   UInt pos = (curr - values) / nb_component;
   erase(pos);
   iterator<R> rit = it;
   return --rit;
 }
 
 
 } // akantu
 
 #endif /* __AKANTU_AKA_ARRAY_TMPL_HH__ */