@@ -37,13 +37,15 @@ UPtrDist distribution_from_xml(pugi::xml_node node);
 
 class DiscreteIndex {
 public:
-  explicit Discrete(pugi::xml_node node);
-  Discrete(const double* p, int n);
+  explicit DiscreteIndex(pugi::xml_node node);
+  DiscreteIndex(const double* p, int n);
+
+  void assign(const double* p, int n);
 
   //! Sample a value from the distribution
   //! \param seed Pseudorandom number seed pointer
   //! \return Sampled value
-  size_t sample(uint64_t* seed) const override;
+  size_t sample(uint64_t* seed) const;
 
   // Properties
   const vector<double>& prob() const { return prob_; }
@@ -81,9 +83,9 @@ class Discrete : public Distribution {
   const vector<size_t>& alias() const { return di_->alias(); }
 
 private:
-  vector<double> x_;             //!< Possible outcomes
-  unique_ptr<DiscreteIndex> di_; //!< discrete probability distribution of
-                                 //!< outcome indices
+  vector<double> x_; //!< Possible outcomes
+  DiscreteIndex di_; //!< discrete probability distribution of
+                     //!< outcome indices
 };
 
 //==============================================================================
 
@@ -114,8 +114,8 @@ class MeshSpatial : public SpatialDistribution {
 
 private:
   int32_t mesh_idx_ {C_NONE};
-  unique_ptr<DiscreteIndex> elem_idx_dist_; //!< Distribution of
-                                            //!< mesh element indices
+  DiscreteIndex elem_idx_dist_; //!< Distribution of
+                                //!< mesh element indices
 };
 
 //==============================================================================
 
@@ -25,8 +25,9 @@ namespace openmc {
 DiscreteIndex::DiscreteIndex(pugi::xml_node node)
 {
   auto params = get_node_array<double>(node, "parameters");
+  std::size_t n = params.size() / 2;
 
-  prob_.assign(params.begin(), params.end());
+  prob_.assign(params.begin() + n, params.end());
 
   this->init_alias();
 }
@@ -38,6 +39,13 @@ DiscreteIndex::DiscreteIndex(const double* p, int n)
   this->init_alias();
 }
 
+void DiscreteIndex::assign(const double* p, int n)
+{
+  prob_.assign(p, p + n);
+
+  this->init_alias();
+}
+
 void DiscreteIndex::init_alias()
 {
   normalize();
@@ -111,21 +119,19 @@ void DiscreteIndex::normalize()
 // Discrete implementation
 //==============================================================================
 
-Discrete::Discrete(pugi::xml_node node)
+Discrete::Discrete(pugi::xml_node node) : di_(node)
 {
   auto params = get_node_array<double>(node, "parameters");
 
   std::size_t n = params.size() / 2;
 
   x_.assign(params.begin(), params.begin() + n);
-  di_ = new DiscreteIndex(params.begin() + n, n)
 }
 
-Discrete::Discrete(const double* x, const double* p, int n)
+Discrete::Discrete(const double* x, const double* p, int n) : di_(p, n)
 {
 
   x_.assign(x, x + n);
-  di_ = new DiscreteIndex(params.begin() + n, n)
 }
 
 double Discrete::sample(uint64_t* seed) const
 
@@ -231,7 +231,7 @@ MeshSpatial::MeshSpatial(pugi::xml_node node)
     }
   }
 
-  elem_idx_dist_ = make_unique<DiscreteIndex>(strengths.data(), n_bins);
+  elem_idx_dist_.assign(strengths.data(), n_bins);
 }
 
 Position MeshSpatial::sample(uint64_t* seed) const
Original file line number	Diff line number	Diff line change
`@@ -25,8 +25,9 @@ namespace openmc {`
`25`	`25`	`DiscreteIndex::DiscreteIndex(pugi::xml_node node)`
`26`	`26`	`{`
`27`	`27`	`auto params = get_node_array<double>(node, "parameters");`
	`28`	`+ std::size_t n = params.size() / 2;`
`28`	`29`
`29`		`- prob_.assign(params.begin(), params.end());`
	`30`	`+ prob_.assign(params.begin() + n, params.end());`
`30`	`31`
`31`	`32`	`this->init_alias();`
`32`	`33`	`}`
`@@ -38,6 +39,13 @@ DiscreteIndex::DiscreteIndex(const double* p, int n)`
`38`	`39`	`this->init_alias();`
`39`	`40`	`}`
`40`	`41`
	`42`	`+void DiscreteIndex::assign(const double* p, int n)`
	`43`	`+{`
	`44`	`+ prob_.assign(p, p + n);`
	`45`	`+`
	`46`	`+ this->init_alias();`
	`47`	`+}`
	`48`	`+`
`41`	`49`	`void DiscreteIndex::init_alias()`
`42`	`50`	`{`
`43`	`51`	`normalize();`
`@@ -111,21 +119,19 @@ void DiscreteIndex::normalize()`
`111`	`119`	`// Discrete implementation`
`112`	`120`	`//==============================================================================`
`113`	`121`
`114`		`-Discrete::Discrete(pugi::xml_node node)`
	`122`	`+Discrete::Discrete(pugi::xml_node node) : di_(node)`
`115`	`123`	`{`
`116`	`124`	`auto params = get_node_array<double>(node, "parameters");`
`117`	`125`
`118`	`126`	`std::size_t n = params.size() / 2;`
`119`	`127`
`120`	`128`	`x_.assign(params.begin(), params.begin() + n);`
`121`		`- di_ = new DiscreteIndex(params.begin() + n, n)`
`122`	`129`	`}`
`123`	`130`
`124`		`-Discrete::Discrete(const double* x, const double* p, int n)`
	`131`	`+Discrete::Discrete(const double* x, const double* p, int n) : di_(p, n)`
`125`	`132`	`{`
`126`	`133`
`127`	`134`	`x_.assign(x, x + n);`
`128`		`- di_ = new DiscreteIndex(params.begin() + n, n)`
`129`	`135`	`}`
`130`	`136`
`131`	`137`	`double Discrete::sample(uint64_t* seed) const`
Original file line number	Diff line number	Diff line change
`@@ -231,7 +231,7 @@ MeshSpatial::MeshSpatial(pugi::xml_node node)`
`231`	`231`	`}`
`232`	`232`	`}`
`233`	`233`
`234`		`- elem_idx_dist_ = make_unique<DiscreteIndex>(strengths.data(), n_bins);`
	`234`	`+ elem_idx_dist_.assign(strengths.data(), n_bins);`
`235`	`235`	`}`
`236`	`236`
`237`	`237`	`Position MeshSpatial::sample(uint64_t* seed) const`