From 7ee86a96b034bc5704bc89e5d5c6b3479c91e2b8 Mon Sep 17 00:00:00 2001
From: WenTao Ou <admin@owent.net>
Date: Fri, 21 Apr 2023 05:27:08 +0800
Subject: [PATCH] Add missing STL header. (#2107)

Signed-off-by: owent <admin@owent.net>
---
 .../opentelemetry/ext/http/client/curl/http_operation_curl.h     | 1 +
 1 file changed, 1 insertion(+)

diff --git a/ext/include/opentelemetry/ext/http/client/curl/http_operation_curl.h b/ext/include/opentelemetry/ext/http/client/curl/http_operation_curl.h
index 55a488f131..65355a05cd 100644
--- a/ext/include/opentelemetry/ext/http/client/curl/http_operation_curl.h
+++ b/ext/include/opentelemetry/ext/http/client/curl/http_operation_curl.h
@@ -13,6 +13,7 @@
 #  include <future>
 #endif
 
+#include <functional>
 #include <map>
 #include <regex>
 #include <sstream>