From 25f30aee8d412d5df8134179df7f682ab3ce311a Mon Sep 17 00:00:00 2001
From: Alfredo Tupone <tupone@gentoo.org>
Date: Thu, 4 Jun 2026 21:22:58 +0200
Subject: [PATCH 1/2] Add sstream include to string_util.h

std::unique_ptr<std::ostringstream> sstream_; require sstream.
Bug raised while building with gcc-17
https://bugs.gentoo.org/976604
---
 cpp/src/arrow/util/string_util.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/cpp/src/arrow/util/string_util.h b/cpp/src/arrow/util/string_util.h
index 3f7803dc92d8..bb5e184d56a3 100644
--- a/cpp/src/arrow/util/string_util.h
+++ b/cpp/src/arrow/util/string_util.h
@@ -19,6 +19,7 @@
 
 #include <memory>
 #include <ostream>
+#include <sstream>
 #include <string>
 #include <type_traits>
 #include <utility>

From bf158a938dfd4e3b3b10738c2391a8bdefc3f885 Mon Sep 17 00:00:00 2001
From: Alfredo Tupone <tupone@gentoo.org>
Date: Fri, 5 Jun 2026 18:25:18 +0200
Subject: [PATCH 2/2] Remove unused sstream include from string_util.h

---
 cpp/src/arrow/util/string_util.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpp/src/arrow/util/string_util.h b/cpp/src/arrow/util/string_util.h
index bb5e184d56a3..da9664c4d400 100644
--- a/cpp/src/arrow/util/string_util.h
+++ b/cpp/src/arrow/util/string_util.h
@@ -17,9 +17,9 @@
 
 #pragma once
 
+#include <iosfwd>
 #include <memory>
 #include <ostream>
-#include <sstream>
 #include <string>
 #include <type_traits>
 #include <utility>