From e05bc82e7bdaf8f25a2b170aa0b4e039d5e549e7 Mon Sep 17 00:00:00 2001
From: conrad <conrad@localhost.localdomain>
Date: Thu, 12 Mar 2026 15:30:34 +1000
Subject: [PATCH] speedups for empty subcubes

---
 include/armadillo_bits/subview_cube_meat.hpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/armadillo_bits/subview_cube_meat.hpp b/include/armadillo_bits/subview_cube_meat.hpp
index 8382fbce..8b0e9c3a 100644
--- a/include/armadillo_bits/subview_cube_meat.hpp
+++ b/include/armadillo_bits/subview_cube_meat.hpp
@@ -1125,6 +1125,8 @@ subview_cube<eT>::each_slice(const std::function< void(Mat<eT>&) >& F)
   {
   arma_debug_sigprint();
   
+  if( (n_rows == 0) || (n_cols == 0) )  { return; }
+  
   Mat<eT> tmp1(n_rows, n_cols, arma_nozeros_indicator());
   Mat<eT> tmp2('j', tmp1.memptr(), n_rows, n_cols);
   
@@ -1153,6 +1155,8 @@ subview_cube<eT>::each_slice(const std::function< void(const Mat<eT>&) >& F) con
   {
   arma_debug_sigprint();
   
+  if( (n_rows == 0) || (n_cols == 0) )  { return; }
+  
         Mat<eT> tmp1(n_rows, n_cols, arma_nozeros_indicator());
   const Mat<eT> tmp2('j', tmp1.memptr(), n_rows, n_cols);