From d5be22c12aedde9265d766baa036021883b97cc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=9F=AC?= <varyshare@foxmail.com>
Date: Sat, 2 Nov 2019 18:16:36 +0800
Subject: [PATCH 1/5] fix cmake in ubuntu16.04 compile error

without the headfile `#include <unistd.h>`

error message
```
error: 'usleep' was not declared in this scope usleep(*);
```
---
 src/Viewer.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Viewer.cc b/src/Viewer.cc
index dec3204f53..967c627df6 100644
--- a/src/Viewer.cc
+++ b/src/Viewer.cc
@@ -20,7 +20,7 @@
 
 #include "Viewer.h"
 #include <pangolin/pangolin.h>
-
+#include <unistd.h>
 #include <mutex>
 
 namespace ORB_SLAM2

From c689aecbc031be86988698b2c268f0c5752048fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=9F=AC?= <varyshare@foxmail.com>
Date: Sat, 2 Nov 2019 18:17:48 +0800
Subject: [PATCH 2/5] fix cmake in ubuntu16.04 compile error

**Reason**: not include the headfile `#include <unistd.h>`

**error message**
```
error: 'usleep' was not declared in this scope usleep(*);
```
---
 src/System.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/System.cc b/src/System.cc
index 8df4157095..0d7a2a5c7a 100644
--- a/src/System.cc
+++ b/src/System.cc
@@ -22,6 +22,7 @@
 
 #include "System.h"
 #include "Converter.h"
+#include <unistd.h>
 #include <thread>
 #include <pangolin/pangolin.h>
 #include <iomanip>

From 3a4ba40af10a1eb4393e146e9ed50d06efc1af90 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=9F=AC?= <varyshare@foxmail.com>
Date: Sat, 2 Nov 2019 18:18:59 +0800
Subject: [PATCH 3/5] fix cmake in ubuntu16.04 compile error

**Reason**: not include the headfile `#include <unistd.h>`

**error message**
```
error: 'usleep' was not declared in this scope usleep(*);
```
---
 src/Tracking.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Tracking.cc b/src/Tracking.cc
index 2273b2ce48..57a45f9ae8 100644
--- a/src/Tracking.cc
+++ b/src/Tracking.cc
@@ -32,7 +32,7 @@
 
 #include"Optimizer.h"
 #include"PnPsolver.h"
-
+#include <unistd.h>
 #include<iostream>
 
 #include<mutex>

From ec7d984c479a949d1083f9923981ae8462ac9f93 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=9F=AC?= <varyshare@foxmail.com>
Date: Sat, 2 Nov 2019 18:20:53 +0800
Subject: [PATCH 4/5] fix cmake in ubuntu16.04 compile error

**Reason**: not include the headfile `#include <unistd.h>`

**error message**
```
error: 'usleep' was not declared in this scope usleep(*);
```
---
 src/LocalMapping.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/LocalMapping.cc b/src/LocalMapping.cc
index 6c87a6e55a..64038fd541 100644
--- a/src/LocalMapping.cc
+++ b/src/LocalMapping.cc
@@ -22,7 +22,7 @@
 #include "LoopClosing.h"
 #include "ORBmatcher.h"
 #include "Optimizer.h"
-
+#include <unistd.h>
 #include<mutex>
 
 namespace ORB_SLAM2

From 970df0cbd4299b41b4f0cd672593d23704fea4f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=9F=AC?= <varyshare@foxmail.com>
Date: Sat, 2 Nov 2019 18:22:21 +0800
Subject: [PATCH 5/5] fix cmake in ubuntu16.04 compile error

**Reason**: not include the headfile `#include <unistd.h>`

**error message**
```
error: 'usleep' was not declared in this scope usleep(*);
```
---
 src/LoopClosing.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/LoopClosing.cc b/src/LoopClosing.cc
index 5e317dd420..0c6beb0997 100644
--- a/src/LoopClosing.cc
+++ b/src/LoopClosing.cc
@@ -27,7 +27,7 @@
 #include "Optimizer.h"
 
 #include "ORBmatcher.h"
-
+#include <unistd.h>
 #include<mutex>
 #include<thread>