From: David Wells <drwells@email.unc.edu>
Date: Sat, 7 Dec 2024 22:45:08 +0000 (-0500)
Subject: AlignedVector: Switch to placement new in two codepaths.
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F17915%2Fhead;p=dealii.git

AlignedVector: Switch to placement new in two codepaths.

Using placement new here is, for scalar types, the same as assignment. For
non-scalar types, this change results in fewer operations since instead of doing
default construction followed by assignment we now just use the copy constructor.
---

diff --git a/include/deal.II/base/aligned_vector.h b/include/deal.II/base/aligned_vector.h
index 4ee1522094..973277db05 100644
--- a/include/deal.II/base/aligned_vector.h
+++ b/include/deal.II/base/aligned_vector.h
@@ -1542,10 +1542,7 @@ AlignedVector<T>::push_back(const T in_data)
   Assert(used_elements_end <= allocated_elements_end, ExcInternalError());
   if (used_elements_end == allocated_elements_end)
     reserve(std::max(2 * capacity(), static_cast<size_type>(16)));
-  if (std::is_trivial_v<T> == false)
-    new (used_elements_end++) T(in_data);
-  else
-    *used_elements_end++ = in_data;
+  new (used_elements_end++) T(in_data);
 }
 
 
@@ -1580,11 +1577,7 @@ AlignedVector<T>::insert_back(ForwardIterator begin, ForwardIterator end)
   const size_type old_size = size();
   reserve(old_size + (end - begin));
   for (; begin != end; ++begin, ++used_elements_end)
-    {
-      if (std::is_trivial_v<T> == false)
-        new (used_elements_end) T;
-      *used_elements_end = *begin;
-    }
+    new (used_elements_end) T(*begin);
 }