From b174dacc85357af41857e4dc858add3ab2e1b6f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Hejl?= <hejl.lukas@gmail.com>
Date: Sat, 7 Aug 2021 08:29:32 +0200
Subject: [PATCH] Added a missing include (GCC 11.1)

---
 src/libslic3r/QuadricEdgeCollapse.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libslic3r/QuadricEdgeCollapse.cpp b/src/libslic3r/QuadricEdgeCollapse.cpp
index a66dbc192..95c7b40d8 100644
--- a/src/libslic3r/QuadricEdgeCollapse.cpp
+++ b/src/libslic3r/QuadricEdgeCollapse.cpp
@@ -1,5 +1,6 @@
 #include "QuadricEdgeCollapse.hpp"
 #include <tuple>
+#include <optional>
 #include "MutablePriorityQueue.hpp"
 #include "SimplifyMeshImpl.hpp"
 #include <tbb/parallel_for.h>