From cc4bbe94067ffc1496f98f10bf752ef8ffb8f3e3 Mon Sep 17 00:00:00 2001
From: Philippe Verney <philippe.verney@f2i-consulting.com>
Date: Thu, 13 Nov 2025 09:49:09 +0100
Subject: [PATCH] Allocate vector block by block when decoding

---
 lang/c++/include/avro/Specific.hh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lang/c++/include/avro/Specific.hh b/lang/c++/include/avro/Specific.hh
index fc28b3f5e4b..cb6b018eef2 100644
--- a/lang/c++/include/avro/Specific.hh
+++ b/lang/c++/include/avro/Specific.hh
@@ -254,6 +254,7 @@ struct codec_traits<std::vector<T>> {
     static void decode(Decoder &d, std::vector<T> &s) {
         s.clear();
         for (size_t n = d.arrayStart(); n != 0; n = d.arrayNext()) {
+            s.reserve(s.size() + n);
             for (size_t i = 0; i < n; ++i) {
                 T t;
                 avro::decode(d, t);