Array: clean-up

- make sure it works with other STIR classes, not just floats etc
- re-instate VectorWithOffset constructors that take both start and end pointers for backwards compatibility

src/include/stir/Array.inl

@@ -100,7 +100,8 @@ Array<num_dimensions, elemT>::Array(const IndexRange<num_dimensions>& range)
   //grow(range);
   this->_allocated_full_data_ptr = new elemT[range.size_all()];
   // info("Array constructor range " + std::to_string(reinterpret_cast<std::size_t>(this->_allocated_full_data_ptr)) + " of size " + std::to_string(range.size_all()));
-  std::fill(this->_allocated_full_data_ptr, this->_allocated_full_data_ptr + range.size_all(), elemT(0));
+  // set elements to zero
+  std::for_each(this->_allocated_full_data_ptr, this->_allocated_full_data_ptr + range.size_all(), [](elemT& e) { assign(e, 0); });
   this->init(range, this->_allocated_full_data_ptr, false);
 }
 

src/include/stir/VectorWithOffset.h

@@ -136,14 +136,30 @@ class VectorWithOffset
   inline VectorWithOffset(const int min_index, const int max_index);
 
   //! Construct a VectorWithOffset of given length pointing to existing data
-  inline explicit 
+  inline
     VectorWithOffset(const int hsz, 
-		     T * const data_ptr);
-
+		     T * const data_ptr,
+		     T * const end_of_data_ptr);
+
+  //! Construct a VectorWithOffset of given length pointing to existing data
+  inline
+    VectorWithOffset(const int hsz, 
+		     T * const data_ptr)
+    : VectorWithOffset(hsz, data_ptr, data_ptr + hsz)
+  {}
+
+  //! Construct a VectorWithOffset with offset \c min_index point to existing data
+  inline 
+    VectorWithOffset(const int min_index, const int max_index, 
+		     T * const data_ptr,
+		     T * const end_of_data_ptr);
+
   //! Construct a VectorWithOffset with offset \c min_index point to existing data
   inline 
     VectorWithOffset(const int min_index, const int max_index, 
-		     T * const data_ptr);
+		     T * const data_ptr)
+    : VectorWithOffset(min_index, max_index, data_ptr, data_ptr + (max_index - min_index + 1))
+  {}
 
   //! copy constructor
   inline VectorWithOffset(const VectorWithOffset &il) ;

src/include/stir/VectorWithOffset.inl

@@ -293,28 +293,30 @@ VectorWithOffset<T>::VectorWithOffset(const int min_index, const int max_index)
 
 template <class T>
 VectorWithOffset<T>::
-VectorWithOffset(const int sz, T * const data_ptr)
+VectorWithOffset(const int sz, 
+		 T * const data_ptr, T * const end_of_data_ptr)   
   : length(static_cast<unsigned>(sz)),
     start(0),
     pointer_access(false),
     _owns_memory_for_data(false)
 {   
   this->begin_allocated_memory = data_ptr;
-  this->end_allocated_memory = data_ptr + sz;
+  this->end_allocated_memory = end_of_data_ptr;
   this->num = this->begin_allocated_memory - this->start;
   this->check_state();
 }
 
 template <class T>
 VectorWithOffset<T>::
-VectorWithOffset(const int min_index, const int max_index, T * const data_ptr)
+VectorWithOffset(const int min_index, const int max_index, 
+		 T * const data_ptr, T * const end_of_data_ptr)   
   : length(static_cast<unsigned>(max_index - min_index) + 1),
     start(min_index),
     pointer_access(false),
     _owns_memory_for_data(false)
 {   
   this->begin_allocated_memory = data_ptr;
-  this->end_allocated_memory = data_ptr + (max_index - min_index + 1);
+  this->end_allocated_memory = end_of_data_ptr;
   this->num = this->begin_allocated_memory - this->start;
   this->check_state();
 }
@@ -335,17 +337,6 @@ VectorWithOffset<T>::~VectorWithOffset()
   _destruct_and_deallocate();
 }		
 
-#if 0
-template <class T>
-VectorWithOffset<T>&
-VectorWithOffset<T>::
-operator=(VectorWithOffset<T> other)
-{
-  swap(*this, other);
-  return *this;
-}
-#endif
-
 template <class T>
 void 
 VectorWithOffset<T>::set_offset(const int min_index)