fix more warnings

src/OpenVolumeMesh/Core/GeometryKernel.hh

@@ -114,7 +114,7 @@ public:
             TopologyKernelT::collect_garbage();
             vertices_.resize(TopologyKernel::n_vertices());
         } else {
-            for (unsigned int i = vertices_.size(); i > 0; --i)
+            for (int i = (int)vertices_.size(); i > 0; --i)
                 if (TopologyKernelT::is_deleted(VertexHandle(i-1)))
                 {
                     vertices_.erase(vertices_.begin() + (i-1));

src/OpenVolumeMesh/Core/OpenVolumeMeshProperty.hh

@@ -139,7 +139,7 @@ public:
 	virtual size_t size_of() const {
 		if (element_size() != OpenVolumeMeshBaseProperty::UnknownSize)
 			return this->OpenVolumeMeshBaseProperty::size_of(n_elements());
-		return std::accumulate(data_.begin(), data_.end(), 0, plus());
+    return std::accumulate(data_.begin(), data_.end(), size_t(0), plus());
 	}
 
 	virtual size_t size_of(size_t _n_elem) const {

src/OpenVolumeMesh/Core/TopologyKernel.cc

@@ -216,7 +216,7 @@ FaceHandle TopologyKernel::add_face(const std::vector<HalfEdgeHandle>& _halfedge
     face_deleted_.push_back(false);
 
     // Get added face's handle
-    FaceHandle fh(faces_.size() - 1);
+    FaceHandle fh((int)faces_.size() - 1);
 
     // Resize props
     resize_fprops(n_faces());