Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/sfm/src/libmv_capi.h

@@ -42,6 +42,8 @@
 #ifndef __OPENCV_SFM_LIBMV_CAPI__
 #define __OPENCV_SFM_LIBMV_CAPI__
 
+#include <memory>
+
 #include "libmv/logging/logging.h"
 
 #include "libmv/correspondence/feature.h"

modules/sfm/src/libmv_light/libmv/base/vector.h

@@ -121,7 +121,7 @@ class vector {
   void reserve(unsigned int size) {
     if (size > size_) {
       T *data = static_cast<T *>(allocate(size));
-#if 0
+#if defined(__GNUC__) && __GNUC__ < 5  // legacy compilers branch
       memcpy(data, data_, sizeof(*data)*size_);
 #else
       for (int i = 0; i < size_; ++i)