From 9223f08b489ebe7f9e5f65d366eb344b3fb85966 Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Wed, 17 Jul 2019 08:48:39 +0800
Subject: [PATCH] Fix build for older gcc

---
 src/App/DocumentObject.h | 1 +
 src/App/Link.h           | 1 +
 src/App/Transactions.h   | 1 +
 src/Gui/Tree.h           | 1 +
 4 files changed, 4 insertions(+)

diff --git a/src/App/DocumentObject.h b/src/App/DocumentObject.h
index 62ab8775ed..52b0390ea8 100644
--- a/src/App/DocumentObject.h
+++ b/src/App/DocumentObject.h
@@ -33,6 +33,7 @@
 #include <Base/Matrix.h>
 #include <CXX/Objects.hxx>
 
+#include <unordered_map>
 #include <bitset>
 #include <boost/signals2.hpp>
 
diff --git a/src/App/Link.h b/src/App/Link.h
index 367dc4dda1..8a0ebc3f1e 100644
--- a/src/App/Link.h
+++ b/src/App/Link.h
@@ -23,6 +23,7 @@
 #ifndef APP_LINK_H
 #define APP_LINK_H
 
+#include <unordered_set>
 #include <boost/signals2.hpp>
 #include <boost/preprocessor/facilities/expand.hpp>
 #include <boost/preprocessor/cat.hpp>
diff --git a/src/App/Transactions.h b/src/App/Transactions.h
index 7d0e619a77..135544c90c 100644
--- a/src/App/Transactions.h
+++ b/src/App/Transactions.h
@@ -24,6 +24,7 @@
 #ifndef APP_TRANSACTION_H
 #define APP_TRANSACTION_H
 
+#include <unordered_map>
 #include <Base/Factory.h>
 #include <Base/Persistence.h>
 #include <App/PropertyContainer.h>
diff --git a/src/Gui/Tree.h b/src/Gui/Tree.h
index 3fb5a3f375..48e9f4dc77 100644
--- a/src/Gui/Tree.h
+++ b/src/Gui/Tree.h
@@ -24,6 +24,7 @@
 #ifndef GUI_TREE_H
 #define GUI_TREE_H
 
+#include <unordered_map>
 #include <QTreeWidget>
 #include <QTime>
 #include <QStyledItemDelegate>