From 2e62298e66cca8f5432b7086feac031e4a600e6b Mon Sep 17 00:00:00 2001
From: Antonio Ospite <ao2@ao2.it>
Date: Thu, 22 Oct 2015 11:11:37 +0200
Subject: [PATCH] Fix a compilation error when using clang++

Clang gives this error:

  In file included from opencv_trail_effect.cpp:25:
  ./Trail.hpp:13:22: error: in-class initialization of non-static data member is a C++11 extension [-Werror,-Wc++11-extensions]
          cv::Mat *background = NULL;
                              ^
  1 error generated.
  <builtin>: recipe for target 'opencv_trail_effect.o' failed
  make: *** [opencv_trail_effect.o] Error 1

Fix it to make compilation succeed.
---
 Trail.hpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Trail.hpp b/Trail.hpp
index e519c94..ecf486a 100644
--- a/Trail.hpp
+++ b/Trail.hpp
@@ -10,7 +10,7 @@ class Trail {
 private:
 	virtual void iterate(cv::Mat& frame, void (*action)(cv::Mat&, Frame *, int, int)) = 0;
 
-	cv::Mat *background = NULL;
+	cv::Mat *background;
 	bool redraw_current_frame;
 	bool persistent;
 
@@ -58,6 +58,7 @@ protected:
 public:
 	Trail(int trail_length, cv::Size frame_size)
 	{
+		background = NULL;
 		redraw_current_frame = false;
 		drawStrategy = frameCopy;
 		persistent = false;
-- 
2.1.4