From 527d57993af98b030e67bf601703e08dd42fd20b Mon Sep 17 00:00:00 2001
From: Marc Glisse <marc.glisse@inria.fr>
Date: Mon, 23 Mar 2020 18:52:49 +0100
Subject: Reuse vector

Reuse + copy should be slightly faster than regrowing each time (and moving)
---
 src/python/include/Persistent_cohomology_interface.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'src/python/include/Persistent_cohomology_interface.h')

diff --git a/src/python/include/Persistent_cohomology_interface.h b/src/python/include/Persistent_cohomology_interface.h
index 89ff5137..3ce40af5 100644
--- a/src/python/include/Persistent_cohomology_interface.h
+++ b/src/python/include/Persistent_cohomology_interface.h
@@ -73,15 +73,17 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol
     std::vector<std::pair<std::vector<int>, std::vector<int>>> persistence_pairs;
     auto const& pairs = Base::get_persistent_pairs();
     persistence_pairs.reserve(pairs.size());
+    std::vector<int> birth;
+    std::vector<int> death;
     for (auto pair : pairs) {
-      std::vector<int> birth;
+      birth.clear();
       if (get<0>(pair) != stptr_->null_simplex()) {
         for (auto vertex : stptr_->simplex_vertex_range(get<0>(pair))) {
           birth.push_back(vertex);
         }
       }
 
-      std::vector<int> death;
+      death.clear();
       if (get<1>(pair) != stptr_->null_simplex()) {
         death.reserve(birth.size()+1);
         for (auto vertex : stptr_->simplex_vertex_range(get<1>(pair))) {
@@ -89,7 +91,7 @@ persistent_cohomology::Persistent_cohomology<FilteredComplex, persistent_cohomol
         }
       }
 
-      persistence_pairs.emplace_back(std::move(birth), std::move(death));
+      persistence_pairs.emplace_back(birth, death);
     }
     return persistence_pairs;
   }
-- 
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