Dynare++ tensor library: use smart pointers in fold() and unfold() methods

dynare++/tl/cc/fs_tensor.cc

@@ -86,10 +86,10 @@ FFSTensor::FFSTensor(const UFSTensor &ut)
 }
 
 /* Here just make a new instance and return the reference. */
-UTensor &
+std::unique_ptr<UTensor>
 FFSTensor::unfold() const
 {
-  return *(new UFSTensor(*this));
+  return std::make_unique<UFSTensor>(*this);
 }
 
 /* Incrementing is easy. We have to increment by calling static method
@@ -203,11 +203,10 @@ UFSTensor::UFSTensor(const FFSTensor &ft)
   unfoldData();
 }
 
-/* Here we just return a reference to new instance of folded tensor. */
-FTensor &
+std::unique_ptr<FTensor>
 UFSTensor::fold() const
 {
-  return *(new FFSTensor(*this));
+  return std::make_unique<FFSTensor>(*this);
 }
 
 // |UFSTensor| increment and decrement

dynare++/tl/cc/fs_tensor.hh

@@ -70,7 +70,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  UTensor&unfold() const override;
+  std::unique_ptr<UTensor> unfold() const override;
   Symmetry
   getSym() const
   {
@@ -114,7 +114,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  FTensor&fold() const override;
+  std::unique_ptr<FTensor> fold() const override;
   Symmetry
   getSym() const
   {

dynare++/tl/cc/gs_tensor.cc

@@ -272,10 +272,10 @@ FGSTensor::increment(IntSequence &v) const
 }
 
 /* Return unfolded version of the tensor. */
-UTensor &
+std::unique_ptr<UTensor>
 FGSTensor::unfold() const
 {
-  return *(new UGSTensor(*this));
+  return std::make_unique<UGSTensor>(*this);
 }
 
 /* Here we implement the contraction
@@ -410,10 +410,10 @@ UGSTensor::decrement(IntSequence &v) const
 }
 
 /* Return a new instance of folded version. */
-FTensor &
+std::unique_ptr<FTensor>
 UGSTensor::fold() const
 {
-  return *(new FGSTensor(*this));
+  return std::make_unique<FGSTensor>(*this);
 }
 
 /* Return an offset of a given index. */

dynare++/tl/cc/gs_tensor.hh

@@ -178,7 +178,7 @@ public:
   {
     tdims.decrement(v);
   }
-  UTensor&unfold() const override;
+  std::unique_ptr<UTensor> unfold() const override;
   const TensorDimens &
   getDims() const
   {
@@ -242,7 +242,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  FTensor&fold() const override;
+  std::unique_ptr<FTensor> fold() const override;
   const TensorDimens &
   getDims() const
   {

dynare++/tl/cc/ps_tensor.cc

@@ -58,12 +58,11 @@ UPSTensor::decrement(IntSequence &v) const
   UTensor::decrement(v, tdims.getNVX());
 }
 
-FTensor &
+std::unique_ptr<FTensor>
 UPSTensor::fold() const
 {
   TL_RAISE("Never should come to this place in UPSTensor::fold");
-  auto *nothing = new FFSTensor(0, 0, 0);
-  return *nothing;
+  return std::make_unique<FFSTensor>(0, 0, 0);
 }
 
 int
@@ -316,12 +315,11 @@ FPSTensor::decrement(IntSequence &v) const
   TL_RAISE("FPSTensor::decrement not implemented");
 }
 
-UTensor &
+std::unique_ptr<UTensor>
 FPSTensor::unfold() const
 {
   TL_RAISE("Unfolding of FPSTensor not implemented");
-  auto *nothing = new UFSTensor(0, 0, 0);
-  return *nothing;
+  return std::make_unique<UFSTensor>(0, 0, 0);
 }
 
 /* We only call |calcOffset| of the |PerTensorDimens2|. */

dynare++/tl/cc/ps_tensor.hh

@@ -206,7 +206,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  FTensor&fold() const override;
+  std::unique_ptr<FTensor> fold() const override;
 
   int getOffset(const IntSequence &v) const override;
   void addTo(FGSTensor &out) const;
@@ -370,7 +370,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  UTensor&unfold() const override;
+  std::unique_ptr<UTensor> unfold() const override;
 
   int getOffset(const IntSequence &v) const override;
   void addTo(FGSTensor &out) const;

dynare++/tl/cc/rfs_tensor.cc

@@ -27,10 +27,10 @@ FRTensor::FRTensor(const URTensor &ut)
 
 /* Here just make a new instance and return the reference. */
 
-UTensor &
+std::unique_ptr<UTensor>
 FRTensor::unfold() const
 {
-  return *(new URTensor(*this));
+  return std::make_unique<URTensor>(*this);
 }
 
 /* Incrementing is easy. The same as for |FFSTensor|. */
@@ -77,10 +77,10 @@ URTensor::URTensor(const FRTensor &ft)
 
 /* Here we just return a reference to new instance of folded tensor. */
 
-FTensor &
+std::unique_ptr<FTensor>
 URTensor::fold() const
 {
-  return *(new FRTensor(*this));
+  return std::make_unique<FRTensor>(*this);
 }
 
 /* Here we just call |UTensor| respective static methods. */
@@ -163,10 +163,10 @@ URSingleTensor::URSingleTensor(const ConstVector &v, int d)
 /* Here we construct |FRSingleTensor| from |URSingleTensor| and return
    its reference. */
 
-FTensor &
+std::unique_ptr<FTensor>
 URSingleTensor::fold() const
 {
-  return *(new FRSingleTensor(*this));
+  return std::make_unique<FRSingleTensor>(*this);
 }
 
 // |FRSingleTensor| conversion from unfolded

dynare++/tl/cc/rfs_tensor.hh

@@ -62,7 +62,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  FTensor&fold() const override;
+  std::unique_ptr<FTensor> fold() const override;
 
   int getOffset(const IntSequence &v) const override;
   int
@@ -98,7 +98,7 @@ public:
 
   void increment(IntSequence &v) const override;
   void decrement(IntSequence &v) const override;
-  UTensor&unfold() const override;
+  std::unique_ptr<UTensor> unfold() const override;
 
   int
   nvar() const
@@ -138,7 +138,7 @@ public:
   = default;
   ~URSingleTensor()
   override = default;
-  FTensor&fold() const override;
+  std::unique_ptr<FTensor> fold() const override;
 };
 
 /* This class represents one column row-oriented tensor. The only way

dynare++/tl/cc/tensor.hh

@@ -49,6 +49,7 @@
 #include "int_sequence.hh"
 #include "twod_matrix.hh"
 
+#include <memory>
 #include <iostream>
 
 /* Here is the |Tensor| class, which is nothing else than a simple subclass
@@ -240,7 +241,7 @@ public:
   {
   }
   ~UTensor() override = default;
-  virtual FTensor &fold() const = 0;
+  virtual std::unique_ptr<FTensor> fold() const = 0;
 
   UTensor &operator=(const UTensor &) = delete;
   UTensor &operator=(UTensor &&) = delete;
@@ -276,7 +277,7 @@ public:
   {
   }
   ~FTensor() override = default;
-  virtual UTensor &unfold() const = 0;
+  virtual std::unique_ptr<UTensor> unfold() const = 0;
 
   FTensor &operator=(const FTensor &) = delete;
   FTensor &operator=(FTensor &&) = delete;

dynare++/tl/testing/tests.cc

@@ -196,8 +196,8 @@ TestRunnable::index_offset(const Symmetry &s, const IntSequence &nvs)
 bool
 TestRunnable::fold_unfold(const FTensor *folded)
 {
-  UTensor *unfolded = &(folded->unfold());
-  FTensor *folded2 = &(unfolded->fold());
+  auto unfolded = folded->unfold();
+  auto folded2 = unfolded->fold();
   folded2->add(-1.0, *folded);
   double normInf = folded2->getNormInf();
   double norm1 = folded2->getNorm1();
@@ -207,8 +207,6 @@ TestRunnable::fold_unfold(const FTensor *folded)
             << "\tdifference norm1:   " << norm1 << '\n';
 
   delete folded;
-  delete unfolded;
-  delete folded2;
 
   return normInf < 1.0e-15;
 }