From c83caaa0da8f26f7db5bbeb28f07a75b4bd5ab98 Mon Sep 17 00:00:00 2001
From: conrad <conrad@localhost.localdomain>
Date: Sat, 18 Jan 2025 23:56:57 +1000
Subject: [PATCH] more efficient handling of expressions

---
 include/armadillo_bits/op_resize_meat.hpp | 32 ++++++++++++++++++-----
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/include/armadillo_bits/op_resize_meat.hpp b/include/armadillo_bits/op_resize_meat.hpp
index 87166b2c..360d093b 100644
--- a/include/armadillo_bits/op_resize_meat.hpp
+++ b/include/armadillo_bits/op_resize_meat.hpp
@@ -34,16 +34,36 @@ op_resize::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_resize>& in)
   const uword new_n_rows = in.aux_uword_a;
   const uword new_n_cols = in.aux_uword_b;
   
-  const unwrap<T1>   tmp(in.m);
-  const Mat<eT>& A = tmp.M;
-  
-  if(&out == &A)
+  if(is_Mat<T1>::value)
     {
-    op_resize::apply_mat_inplace(out, new_n_rows, new_n_cols);
+    const unwrap<T1>   U(in.m);
+    const Mat<eT>& A = U.M;
+    
+    if(&out == &A)
+      {
+      op_resize::apply_mat_inplace(out, new_n_rows, new_n_cols);
+      }
+    else
+      {
+      op_resize::apply_mat_noalias(out, A, new_n_rows, new_n_cols);
+      }
     }
   else
     {
-    op_resize::apply_mat_noalias(out, A, new_n_rows, new_n_cols);
+    const quasi_unwrap<T1> U(in.m);
+    
+    if(U.is_alias(out))
+      {
+      Mat<eT> tmp;
+      
+      op_resize::apply_mat_noalias(tmp, U.M, new_n_rows, new_n_cols);
+      
+      out.steal_mem(tmp);
+      }
+    else
+      {
+      op_resize::apply_mat_noalias(out, U.M, new_n_rows, new_n_cols);
+      }
     }
   }