patch bump

docs.html

@@ -9655,7 +9655,7 @@ vec b = diff(a);
 </li>
 <br>
 <li>
-<b>Caveat:</b> <a href="#norm">norm()</a> is preferred for calculating the 2-norm, as it reduces the incidence of numerical underflows and overflows
+<b>Caveat:</b> to obtain the Euclidean norm, use the more robust <a href="#norm">norm(x)</a> instead of <i>sqrt(dot(x,x))</i>
 </li>
 <br>
 <li>

include/armadillo_bits/Base_meat.hpp

@@ -957,7 +957,7 @@ Base_extra_yes<elem_type,derived>::is_sympd(typename get_pod_type<elem_type>::re
   
   typedef typename get_pod_type<elem_type>::result T;
   
-  arma_conform_check( ((tol >= T(0)) == false), "is_sympd(): parameter 'tol' must be > 0" );
+  arma_conform_check( ((tol >= T(0)) == false), "is_sympd(): parameter 'tol' must be >= 0" );
   
   Mat<elem_type> X = static_cast<const derived&>(*this);
   

include/armadillo_bits/Mat_meat.hpp

@@ -2544,7 +2544,7 @@ Mat<eT>::Mat(const subview_elem1<eT,T1>& X, const arma_vec_indicator&, const uhw
   {
   arma_debug_sigprint_this(this);
   
-  (*this).operator=(X);
+  subview_elem1<eT,T1>::extract_noalias(*this, X);
   }
 
 
@@ -2563,7 +2563,7 @@ Mat<eT>::Mat(const subview_elem1<eT,T1>& X)
   {
   arma_debug_sigprint_this(this);
   
-  (*this).operator=(X);
+  subview_elem1<eT,T1>::extract_noalias(*this, X);
   }
 
 
@@ -2672,7 +2672,7 @@ Mat<eT>::Mat(const subview_elem2<eT,T1,T2>& X, const arma_vec_indicator&, const
   {
   arma_debug_sigprint_this(this);
   
-  (*this).operator=(X);
+  subview_elem2<eT,T1,T2>::extract_noalias(*this, X);
   }
 
 
@@ -2691,7 +2691,7 @@ Mat<eT>::Mat(const subview_elem2<eT,T1,T2>& X)
   {
   arma_debug_sigprint_this(this);
   
-  (*this).operator=(X);
+  subview_elem2<eT,T1,T2>::extract_noalias(*this, X);
   }
 
 

include/armadillo_bits/Proxy.hpp

@@ -1537,7 +1537,7 @@ struct Proxy_xtrans_default< Op<T1, op_htrans> >
   arma_inline aligned_ea_type get_aligned_ea() const { return Q; }
   
   template<typename eT2>
-  arma_inline bool is_alias(const Mat<eT2>& X) const { return void_ptr(&(U.M)) == void_ptr(&X); }
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return U.is_alias(X); }
   
   template<typename eT2>
   arma_inline bool has_overlap(const subview<eT2>& X) const { return is_alias(X.m); }
@@ -1578,7 +1578,7 @@ struct Proxy_xtrans_default< Op<T1, op_strans> >
   arma_inline aligned_ea_type get_aligned_ea() const { return Q; }
   
   template<typename eT2>
-  arma_inline bool is_alias(const Mat<eT2>& X) const { return void_ptr(&(U.M)) == void_ptr(&X); }
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return U.is_alias(X); }
   
   template<typename eT2>
   arma_inline bool has_overlap(const subview<eT2>& X) const { return is_alias(X.m); }
@@ -2441,7 +2441,7 @@ struct Proxy_vectorise_col_mat< Op<T1, op_vectorise_col> >
   arma_inline aligned_ea_type get_aligned_ea() const { return Q;          }
   
   template<typename eT2>
-  arma_inline bool is_alias(const Mat<eT2>& X) const { return ( void_ptr(&X) == void_ptr(&(U.M)) ); }
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return U.is_alias(X); }
   
   template<typename eT2>
   arma_inline bool has_overlap(const subview<eT2>& X) const { return is_alias(X.m); }

include/armadillo_bits/SpBase_bones.hpp

@@ -52,8 +52,6 @@ struct SpBase
   {
   arma_inline const derived& get_ref() const;
   
-  arma_inline bool is_alias(const SpMat<elem_type>& X) const;
-  
   arma_warn_unused inline const SpOp<derived,spop_htrans>  t() const;  //!< Hermitian transpose
   arma_warn_unused inline const SpOp<derived,spop_htrans> ht() const;  //!< Hermitian transpose
   arma_warn_unused inline const SpOp<derived,spop_strans> st() const;  //!< simple transpose

include/armadillo_bits/SpBase_meat.hpp

@@ -31,16 +31,6 @@ SpBase<elem_type,derived>::get_ref() const
 
 
 
-template<typename elem_type, typename derived>
-arma_inline
-bool
-SpBase<elem_type,derived>::is_alias(const SpMat<elem_type>& X) const
-  {
-  return (*this).get_ref().is_alias(X);
-  }
-
-
-
 template<typename elem_type, typename derived>
 inline
 const SpOp<derived, spop_htrans>

include/armadillo_bits/SpGlue_bones.hpp

@@ -35,7 +35,8 @@ struct SpGlue : public SpBase< typename T1::elem_type, SpGlue<T1, T2, spglue_typ
   inline  SpGlue(const T1& in_A, const T2& in_B, const elem_type in_aux);
   inline ~SpGlue();
   
-  arma_inline bool is_alias(const SpMat<elem_type>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
   
   const T1&       A;    //!< first operand;  must be derived from SpBase
   const T2&       B;    //!< second operand; must be derived from SpBase

include/armadillo_bits/SpGlue_meat.hpp

@@ -54,9 +54,10 @@ SpGlue<T1,T2,spglue_type>::~SpGlue()
 
 
 template<typename T1, typename T2, typename spglue_type>
+template<typename eT2>
 arma_inline
 bool
-SpGlue<T1,T2,spglue_type>::is_alias(const SpMat<typename T1::elem_type>& X) const
+SpGlue<T1,T2,spglue_type>::is_alias(const SpMat<eT2>& X) const
   {
   return (A.is_alias(X) || B.is_alias(X));
   }

include/armadillo_bits/SpMat_bones.hpp

@@ -647,7 +647,8 @@ class SpMat : public SpBase< eT, SpMat<eT> >
   template<typename eT2, typename T1, typename Functor> inline void init_xform_mt(const SpBase<eT2,T1>& x, const Functor& func);
   
   //! don't use this unless you're writing internal Armadillo code
-  arma_inline bool is_alias(const SpMat<eT>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
   
   
   protected:

include/armadillo_bits/SpMat_meat.hpp

@@ -6015,11 +6015,14 @@ SpMat<eT>::init_xform_mt(const SpBase<eT2,T1>& A, const Functor& func)
 
 
 template<typename eT>
+template<typename eT2>
 arma_inline
 bool
-SpMat<eT>::is_alias(const SpMat<eT>& X) const
+SpMat<eT>::is_alias(const SpMat<eT2>& X) const
   {
-  return (&X == this);
+  arma_debug_sigprint();
+  
+  return (is_same_type<eT,eT2>::yes) && (void_ptr(this) == void_ptr(&X));
   }
 
 

include/armadillo_bits/SpOp_bones.hpp

@@ -36,7 +36,8 @@ struct SpOp : public SpBase< typename T1::elem_type, SpOp<T1, op_type> >
   inline          SpOp(const T1& in_m, const uword     in_aux_uword_a, const uword in_aux_uword_b);
   inline         ~SpOp();
   
-  arma_inline bool is_alias(const SpMat<elem_type>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
   
   const T1&       m;            //!< the operand; must be derived from SpBase
         elem_type aux;          //!< auxiliary data, using the element type as used by T1

include/armadillo_bits/SpOp_meat.hpp

@@ -64,9 +64,10 @@ SpOp<T1, op_type>::~SpOp()
 
 
 template<typename T1, typename op_type>
+template<typename eT2>
 arma_inline
 bool
-SpOp<T1, op_type>::is_alias(const SpMat<typename T1::elem_type>& X) const
+SpOp<T1, op_type>::is_alias(const SpMat<eT2>& X) const
   {
   return m.is_alias(X);
   }

include/armadillo_bits/SpSubview_bones.hpp

@@ -321,7 +321,8 @@ class SpSubview : public SpBase< eT, SpSubview<eT> >
   inline const_row_iterator end_row(const uword row_num) const;
   
   //! don't use this unless you're writing internal Armadillo code
-  arma_inline bool is_alias(const SpMat<eT>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
   
   
   private:

include/armadillo_bits/SpSubview_col_list_bones.hpp

@@ -87,6 +87,8 @@ class SpSubview_col_list : public SpBase< eT, SpSubview_col_list<eT,T1> >
   inline static void schur_inplace(SpMat<eT>& out, const SpSubview_col_list& in);
   inline static void   div_inplace(SpMat<eT>& out, const SpSubview_col_list& in);
   
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
   
   friend class SpMat<eT>;
   };

include/armadillo_bits/SpSubview_col_list_meat.hpp

@@ -714,4 +714,15 @@ SpSubview_col_list<eT,T1>::div_inplace(SpMat<eT>& out, const SpSubview_col_list&
 
 
 
+template<typename eT, typename T1>
+template<typename eT2>
+arma_inline
+bool
+SpSubview_col_list<eT,T1>::is_alias(const SpMat<eT2>& X) const
+  {
+  return m.is_alias(X);
+  }
+
+
+
 //! @}

include/armadillo_bits/SpSubview_meat.hpp

@@ -1786,9 +1786,10 @@ SpSubview<eT>::end_row(const uword row_num) const
 
 
 template<typename eT>
+template<typename eT2>
 arma_inline
 bool
-SpSubview<eT>::is_alias(const SpMat<eT>& X) const
+SpSubview<eT>::is_alias(const SpMat<eT2>& X) const
   {
   return m.is_alias(X);
   }

include/armadillo_bits/arma_version.hpp

@@ -23,7 +23,7 @@
 
 #define ARMA_VERSION_MAJOR 15
 #define ARMA_VERSION_MINOR 2
-#define ARMA_VERSION_PATCH 6
+#define ARMA_VERSION_PATCH 8
 #define ARMA_VERSION_NAME  "Medium Roast Deluxe"
 
 

include/armadillo_bits/field_meat.hpp

@@ -94,7 +94,9 @@ field<oT>::field(const subview_field<oT>& X)
   {
   arma_debug_sigprint_this(this);
   
-  (*this).operator=(X);
+  init(X.n_rows, X.n_cols, X.n_slices);
+  
+  subview_field<oT>::extract(*this, X);
   }
 
 
@@ -107,7 +109,20 @@ field<oT>::operator=(const subview_field<oT>& X)
   {
   arma_debug_sigprint();
   
-  subview_field<oT>::extract(*this, X);
+  const bool alias = (this == &(X.f));
+  
+  if(alias == false)
+    {
+    (*this).init(X.n_rows, X.n_cols, X.n_slices);
+    
+    subview_field<oT>::extract(*this, X);
+    }
+  else
+    {
+    field<oT> tmp(X);
+    
+    (*this).operator=(std::move(tmp));
+    }
   
   return *this;
   }

include/armadillo_bits/mtSpOp_meat.hpp

@@ -94,7 +94,7 @@ arma_inline
 bool
 mtSpOp<out_eT, T1, op_type>::is_alias(const SpMat<eT2>& X) const
   {
-  return (void_ptr(&X) == void_ptr(&m));
+  return m.is_alias(X);
   }
 
 

include/armadillo_bits/mtSpReduceOp_bones.hpp

@@ -50,6 +50,9 @@ struct mtSpReduceOp : public SpBase< out_eT, mtSpReduceOp<out_eT, T1, op_type> >
   inline          mtSpReduceOp(const T1& in_m, const uword in_aux_uword_a, const uword in_aux_uword_b);
   inline         ~mtSpReduceOp();
   
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
+  
   const T1&   m;            //!< the operand; must be derived from SpBase
         uword aux_uword_a;  //!< auxiliary data, uword format
         uword aux_uword_b;  //!< auxiliary data, uword format

include/armadillo_bits/mtSpReduceOp_meat.hpp

@@ -52,4 +52,15 @@ mtSpReduceOp<out_eT, T1, op_type>::~mtSpReduceOp()
 
 
 
+template<typename out_eT, typename T1, typename op_type>
+template<typename eT2>
+arma_inline
+bool
+mtSpReduceOp<out_eT, T1, op_type>::is_alias(const SpMat<eT2>& X) const
+  {
+  return m.is_alias(X);
+  }
+
+
+
 //! @}

include/armadillo_bits/spdiagview_bones.hpp

@@ -105,6 +105,9 @@ class spdiagview : public SpBase< eT, spdiagview<eT> >
   inline static void extract(SpMat<eT>& out, const spdiagview& in);
   inline static void extract(  Mat<eT>& out, const spdiagview& in);
   
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
+  
   
   friend class SpMat<eT>;
   };

include/armadillo_bits/spdiagview_meat.hpp

@@ -1076,4 +1076,15 @@ spdiagview<eT>::randn()
 
 
 
+template<typename eT>
+template<typename eT2>
+arma_inline
+bool
+spdiagview<eT>::is_alias(const SpMat<eT2>& X) const
+  {
+  return m.is_alias(X);
+  }
+
+
+
 //! @}

include/armadillo_bits/subview_elem1_bones.hpp

@@ -90,6 +90,8 @@ class subview_elem1 : public Base< eT, subview_elem1<eT,T1> >
   template<typename T2> inline void operator%= (const Base<eT,T2>& x);
   template<typename T2> inline void operator/= (const Base<eT,T2>& x);
   
+  inline static void extract_noalias(Mat<eT>& out, const subview_elem1& in);
+  
   inline static void extract(Mat<eT>& out, const subview_elem1& in);
   
   template<typename op_type> inline static void mat_inplace_op(Mat<eT>& out, const subview_elem1& in);

include/armadillo_bits/subview_elem1_meat.hpp

@@ -759,6 +759,55 @@ subview_elem1<eT,T1>::operator/= (const Base<eT,T2>& x)
 
 
 
+template<typename eT, typename T1>
+inline
+void
+subview_elem1<eT,T1>::extract_noalias(Mat<eT>& out, const subview_elem1<eT,T1>& in)
+  {
+  arma_debug_sigprint();
+  
+  const quasi_unwrap<T1> tmp1(in.a.get_ref());
+  const umat& aa = tmp1.M;
+  
+  if(resolves_to_vector<T1>::no)
+    {
+    arma_conform_check( ( (aa.is_vec() == false) && (aa.is_empty() == false) ), "Mat::elem(): given object must be a vector" );
+    }
+  
+  const uword* aa_mem    = aa.memptr();
+  const uword  aa_n_elem = aa.n_elem;
+  
+  const eT*   m_mem    = in.m.memptr();
+  const uword m_n_elem = in.m.n_elem;
+  
+  out.set_size(aa_n_elem, 1);
+  
+  eT* out_mem = out.memptr();
+  
+  uword i,j;
+  for(i=0, j=1; j<aa_n_elem; i+=2, j+=2)
+    {
+    const uword ii = aa_mem[i];
+    const uword jj = aa_mem[j];
+    
+    arma_conform_check_bounds( ( (ii >= m_n_elem) || (jj >= m_n_elem) ), "Mat::elem(): index out of bounds" );
+    
+    out_mem[i] = m_mem[ii];
+    out_mem[j] = m_mem[jj];
+    }
+  
+  if(i < aa_n_elem)
+    {
+    const uword ii = aa_mem[i];
+    
+    arma_conform_check_bounds( (ii >= m_n_elem) , "Mat::elem(): index out of bounds" );
+    
+    out_mem[i] = m_mem[ii];
+    }
+  }
+
+
+
 template<typename eT, typename T1>
 inline
 void
@@ -777,12 +826,12 @@ subview_elem1<eT,T1>::extract(Mat<eT>& actual_out, const subview_elem1<eT,T1>& i
   const uword* aa_mem    = aa.memptr();
   const uword  aa_n_elem = aa.n_elem;
   
-  const Mat<eT>& m_local = in.m;
+  const Mat<eT>& m = in.m;
   
-  const eT*   m_mem    = m_local.memptr();
-  const uword m_n_elem = m_local.n_elem;
+  const eT*   m_mem    = m.memptr();
+  const uword m_n_elem = m.n_elem;
   
-  const bool alias = (&actual_out == &m_local);
+  const bool alias = (&actual_out == &m);
   
   if(alias)  { arma_debug_print("subview_elem1::extract(): aliasing detected"); }
   

include/armadillo_bits/subview_elem2_bones.hpp

@@ -98,6 +98,8 @@ class subview_elem2 : public Base< eT, subview_elem2<eT,T1,T2> >
   template<typename expr> inline void operator%= (const SpBase<eT,expr>& x);
   template<typename expr> inline void operator/= (const SpBase<eT,expr>& x);
   
+  inline static void extract_noalias(Mat<eT>& out, const subview_elem2& in);
+  
   inline static void extract(Mat<eT>& out, const subview_elem2& in);
   
   inline static void  plus_inplace(Mat<eT>& out, const subview_elem2& in);

include/armadillo_bits/subview_elem2_meat.hpp

@@ -917,6 +917,121 @@ subview_elem2<eT,T1,T2>::operator/= (const SpBase<eT,expr>& x)
 
 
 
+template<typename eT, typename T1, typename T2>
+inline
+void
+subview_elem2<eT,T1,T2>::extract_noalias(Mat<eT>& out, const subview_elem2<eT,T1,T2>& in)
+  {
+  arma_debug_sigprint();
+  
+  const Mat<eT>& m = in.m;
+  
+  const uword m_n_rows = m.n_rows;
+  const uword m_n_cols = m.n_cols;
+  
+  if( (in.all_rows == false) && (in.all_cols == false) )
+    {
+    const quasi_unwrap<T1> tmp1(in.base_ri.get_ref());
+    const quasi_unwrap<T2> tmp2(in.base_ci.get_ref());
+    
+    const umat& ri = tmp1.M;
+    const umat& ci = tmp2.M;
+    
+    arma_conform_check
+      (
+      ( ((ri.is_vec() == false) && (ri.is_empty() == false)) || ((ci.is_vec() == false) && (ci.is_empty() == false)) ),
+      "Mat::elem(): given object must be a vector"
+      );
+    
+    const uword* ri_mem    = ri.memptr();
+    const uword  ri_n_elem = ri.n_elem;
+    
+    const uword* ci_mem    = ci.memptr();
+    const uword  ci_n_elem = ci.n_elem;
+    
+    out.set_size(ri_n_elem, ci_n_elem);
+    
+    eT*   out_mem   = out.memptr();
+    uword out_count = 0;
+    
+    for(uword ci_count=0; ci_count < ci_n_elem; ++ci_count)
+      {
+      const uword col = ci_mem[ci_count];
+      
+      arma_conform_check_bounds( (col >= m_n_cols), "Mat::elem(): index out of bounds" );
+      
+      for(uword ri_count=0; ri_count < ri_n_elem; ++ri_count)
+        {
+        const uword row = ri_mem[ri_count];
+        
+        arma_conform_check_bounds( (row >= m_n_rows), "Mat::elem(): index out of bounds" );
+        
+        out_mem[out_count] = m.at(row,col);
+        ++out_count;
+        }
+      }
+    }
+  else
+  if( (in.all_rows == true) && (in.all_cols == false) )
+    {
+    const quasi_unwrap<T2> tmp2(in.base_ci.get_ref());
+    
+    const umat& ci = tmp2.M;
+    
+    arma_conform_check
+      (
+      ( (ci.is_vec() == false) && (ci.is_empty() == false) ),
+      "Mat::elem(): given object must be a vector"
+      );
+    
+    const uword* ci_mem    = ci.memptr();
+    const uword  ci_n_elem = ci.n_elem;
+    
+    out.set_size(m_n_rows, ci_n_elem);
+    
+    for(uword ci_count=0; ci_count < ci_n_elem; ++ci_count)
+      {
+      const uword col = ci_mem[ci_count];
+      
+      arma_conform_check_bounds( (col >= m_n_cols), "Mat::elem(): index out of bounds" );
+      
+      arrayops::copy( out.colptr(ci_count), m.colptr(col), m_n_rows );
+      }
+    }
+  else
+  if( (in.all_rows == false) && (in.all_cols == true) )
+    {
+    const quasi_unwrap<T1> tmp1(in.base_ri.get_ref());
+    
+    const umat& ri = tmp1.M;
+    
+    arma_conform_check
+      (
+      ( (ri.is_vec() == false) && (ri.is_empty() == false) ),
+      "Mat::elem(): given object must be a vector"
+      );
+    
+    const uword* ri_mem    = ri.memptr();
+    const uword  ri_n_elem = ri.n_elem;
+    
+    out.set_size(ri_n_elem, m_n_cols);
+    
+    for(uword col=0; col < m_n_cols; ++col)
+      {
+      for(uword ri_count=0; ri_count < ri_n_elem; ++ri_count)
+        {
+        const uword row = ri_mem[ri_count];
+        
+        arma_conform_check_bounds( (row >= m_n_rows), "Mat::elem(): index out of bounds" );
+        
+        out.at(ri_count,col) = m.at(row,col);
+        }
+      }
+    }
+  }
+
+
+
 template<typename eT, typename T1, typename T2>
 inline
 void
@@ -924,12 +1039,12 @@ subview_elem2<eT,T1,T2>::extract(Mat<eT>& actual_out, const subview_elem2<eT,T1,
   {
   arma_debug_sigprint();
   
-  Mat<eT>& m_local = const_cast< Mat<eT>& >(in.m);
+  const Mat<eT>& m = in.m;
   
-  const uword m_n_rows = m_local.n_rows;
-  const uword m_n_cols = m_local.n_cols;
+  const uword m_n_rows = m.n_rows;
+  const uword m_n_cols = m.n_cols;
   
-  const bool alias = (&actual_out == &m_local);
+  const bool alias = (&actual_out == &m);
   
   if(alias)  { arma_debug_print("subview_elem2::extract(): aliasing detected"); }
   
@@ -973,7 +1088,7 @@ subview_elem2<eT,T1,T2>::extract(Mat<eT>& actual_out, const subview_elem2<eT,T1,
         
         arma_conform_check_bounds( (row >= m_n_rows), "Mat::elem(): index out of bounds" );
         
-        out_mem[out_count] = m_local.at(row,col);
+        out_mem[out_count] = m.at(row,col);
         ++out_count;
         }
       }
@@ -981,7 +1096,7 @@ subview_elem2<eT,T1,T2>::extract(Mat<eT>& actual_out, const subview_elem2<eT,T1,
   else
   if( (in.all_rows == true) && (in.all_cols == false) )
     {
-    const unwrap_check_mixed<T2> tmp2(in.base_ci.get_ref(), m_local);
+    const unwrap_check_mixed<T2> tmp2(in.base_ci.get_ref(), m);
     
     const umat& ci = tmp2.M;
     
@@ -1002,13 +1117,13 @@ subview_elem2<eT,T1,T2>::extract(Mat<eT>& actual_out, const subview_elem2<eT,T1,
       
       arma_conform_check_bounds( (col >= m_n_cols), "Mat::elem(): index out of bounds" );
       
-      arrayops::copy( out.colptr(ci_count), m_local.colptr(col), m_n_rows );
+      arrayops::copy( out.colptr(ci_count), m.colptr(col), m_n_rows );
       }
     }
   else
   if( (in.all_rows == false) && (in.all_cols == true) )
     {
-    const unwrap_check_mixed<T1> tmp1(in.base_ri.get_ref(), m_local);
+    const unwrap_check_mixed<T1> tmp1(in.base_ri.get_ref(), m);
     
     const umat& ri = tmp1.M;
     
@@ -1031,7 +1146,7 @@ subview_elem2<eT,T1,T2>::extract(Mat<eT>& actual_out, const subview_elem2<eT,T1,
         
         arma_conform_check_bounds( (row >= m_n_rows), "Mat::elem(): index out of bounds" );
         
-        out.at(ri_count,col) = m_local.at(row,col);
+        out.at(ri_count,col) = m.at(row,col);
         }
       }
     }

include/armadillo_bits/subview_field_meat.hpp

@@ -507,24 +507,17 @@ subview_field<oT>::fill(const oT& x)
 template<typename oT>
 inline
 void
-subview_field<oT>::extract(field<oT>& actual_out, const subview_field<oT>& in)
+subview_field<oT>::extract(field<oT>& out, const subview_field<oT>& in)
   {
   arma_debug_sigprint();
   
-  //
-  const bool alias = (&actual_out == &in.f);
-  
-  field<oT>* tmp = (alias) ? new field<oT> : nullptr;
-  field<oT>& out = (alias) ? (*tmp)        : actual_out;
-  
-  //
+  // NOTE: we're assuming that the field has already been set to the correct size and there is no aliasing;
+  // size setting and alias checking is done by either the field constructor or operator=()
   
   const uword n_rows   = in.n_rows;
   const uword n_cols   = in.n_cols;
   const uword n_slices = in.n_slices;
   
-  out.set_size(n_rows, n_cols, n_slices);
-  
   arma_debug_print(arma_str::format("out.n_rows: %u; out.n_cols: %u; out.n_slices: %u; in.f.n_rows: %u; in.f.n_cols: %u; in.f.n_slices: %u") % out.n_rows % out.n_cols % out.n_slices % in.f.n_rows % in.f.n_cols % in.f.n_slices);
   
   if(n_slices == 1)
@@ -544,12 +537,6 @@ subview_field<oT>::extract(field<oT>& actual_out, const subview_field<oT>& in)
       out.at(row,col,slice) = in.at(row,col,slice);
       }
     }
-  
-  if(alias)
-    {
-    actual_out = out;
-    delete tmp;
-    }
   }
 
 

include/armadillo_bits/unwrap.hpp

@@ -38,6 +38,9 @@ struct unwrap_default
     }
   
   const Mat<eT> M;
+  
+  template<typename eT2>
+  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
   };
 
 
@@ -55,6 +58,9 @@ struct unwrap_fixed
     }
   
   const T1& M;
+  
+  template<typename eT2>
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return (void_ptr(&M) == void_ptr(&X)); }
   };
 
 
@@ -94,6 +100,9 @@ struct unwrap< Mat<eT> >
     }
   
   const Mat<eT>& M;
+  
+  template<typename eT2>
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&M) == void_ptr(&X)); }
   };
 
 
@@ -111,6 +120,9 @@ struct unwrap< Row<eT> >
     }
   
   const Row<eT>& M;
+  
+  template<typename eT2>
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&M) == void_ptr(&X)); }
   };
 
 
@@ -128,6 +140,9 @@ struct unwrap< Col<eT> >
     }
   
   const Col<eT>& M;
+  
+  template<typename eT2>
+  arma_inline bool is_alias(const Mat<eT2>& X) const { return (is_same_type<eT,eT2>::yes) && (void_ptr(&M) == void_ptr(&X)); }
   };
 
 
@@ -145,6 +160,9 @@ struct unwrap< subview_col<eT> >
     }
   
   const Col<eT> M;
+  
+  template<typename eT2>
+  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
   };
 
 
@@ -162,6 +180,9 @@ struct unwrap< subview_cols<eT> >
     }
   
   const Mat<eT> M;
+  
+  template<typename eT2>
+  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
   };
 
 
@@ -179,6 +200,9 @@ struct unwrap< mtGlue<out_eT, T1, T2, glue_type> >
     }
   
   const Mat<out_eT> M;
+  
+  template<typename eT2>
+  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
   };
 
 
@@ -196,6 +220,9 @@ struct unwrap< mtOp<out_eT, T1, op_type> >
     }
   
   const Mat<out_eT> M;
+  
+  template<typename eT2>
+  constexpr bool is_alias(const Mat<eT2>&) const { return false; }
   };
 
 
@@ -311,7 +338,6 @@ struct quasi_unwrap< Mat<eT> >
 template<typename eT>
 struct quasi_unwrap< Row<eT> >
   {
-  
   inline
   quasi_unwrap(const Row<eT>& A)
     : M(A)