Set stricter warning rules for gcc

modules/flann/include/opencv2/flann/any.h

@@ -46,6 +46,7 @@ struct base_any_policy
     virtual ::size_t get_size() = 0;
     virtual const std::type_info& type() = 0;
     virtual void print(std::ostream& out, void* const* src) = 0;
+    virtual ~base_any_policy() {}
 };
 
 template<typename T>

modules/flann/include/opencv2/flann/dynamic_bitset.h

@@ -35,6 +35,9 @@
 #ifndef OPENCV_FLANN_DYNAMIC_BITSET_H_
 #define OPENCV_FLANN_DYNAMIC_BITSET_H_
 
+#ifndef FLANN_USE_BOOST
+#  define FLANN_USE_BOOST 0
+#endif
 //#define FLANN_USE_BOOST 1
 #if FLANN_USE_BOOST
 #include <boost/dynamic_bitset.hpp>

modules/flann/include/opencv2/flann/lsh_table.h

@@ -40,6 +40,11 @@
 #include <iomanip>
 #include <limits.h>
 // TODO as soon as we use C++0x, use the code in USE_UNORDERED_MAP
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
+#  define USE_UNORDERED_MAP 1
+#else
+#  define USE_UNORDERED_MAP 0
+#endif
 #if USE_UNORDERED_MAP
 #include <unordered_map>
 #else